Chaos Emerald


 * For other uses of the term, see Chaos Emerald (disambiguation). For other subjects named "Emerald", see Emerald.

The Chaos Emeralds (カオスエメラルド), also known as the miracle gems or gems of miracles, are objects in the Sonic the Hedgehog series. They are seven ancient emeralds and mystical relics tied to the Master Emerald that possess powerful properties and abilities. Those that hold the Chaos Emeralds can use their powers for a variety of things, such as initiating a super transformation, powering machines, and warping time and space. Anyone who combines all seven Chaos Emeralds can control ultimate power. Even when not including their mystical powers, the Chaos Emeralds' monetary value and beauty make them prime targets of treasure hunters who seek to make a mint.

Throughout history, the Chaos Emeralds have been the center of countless world-threatening conflicts and have been targeted by multiple factions on both Earth and beyond, who seek them for their near-limitless powers. In the hands of villains they have been used for doomsday weapons and schemes for world domination, and in the hands of heroes they have been used to save the world. Over time, the Emeralds have been gathered multiple times, though they tend to scatter themselves after each usage and reset the hunt for them.

In the early games of the series, the Chaos Emeralds were more like "bonus" items, but since Sonic Adventure, they have become necessary plot devices, and that trend has continued throughout the later games.

Powers and traits
Described as holding enough power to let their possessor control the whole world, each Chaos Emerald is said to possess mystical properties and contain unlimited amounts of highly potent and powerful chaos energy that is said to give life to all things. Even alone, their power is unmatched by pretty much anything else in the universe, except by the Power of the Stars and the Master Emerald; just one Emerald can grant access to unlimited power and radiates enough chaos energy to repel the incomplete Time Eater, power an entire Gaia Temple, and destabilize the crust of a planet. It is often said that those whom combine all seven Chaos Emeralds will gain ultimate power and unlimited energy.

The power of each Chaos Emerald is described as being able to “transform thoughts into power”; by "sensing" people's thoughts, the Chaos Emeralds can generate the chaos energy they contain which make them everlasting sources of energy. Oppositely, the Emeralds can absorb the chaos energy exposed to them. By focusing one's thoughts, the Emeralds can even bend reality to achieve certain feats, such as showing fabricated visions, performing rituals, reviving the recently deceased and even make them move on their own. Additionally, each Emerald can float in midair on its own power.

The Chaos Emeralds' power can be harnessed with or without physical contact, and can be done so over great distances. When harnessed by living beings, they allow different Chaos Powers, such as Chaos Control, and can occasionally enhance the wielder's abilities. Harnessing all seven Chaos Emeralds will bestow a person with a Super State, a form that grants flight, invulnerability, different Chaos Powers, and increased innate talents. Additionally, a Super State user can transfer their power to others to bestow them with a Super State of their own. However, Super States generally do not last long, as they consume tremendous amounts of energy. The Emeralds' power can also be harnessed by machinery, such as the Eclipse Cannon, for the purpose of powering them. Potentially, their power can also be used for nuclear or laser-based weaponry.

The type of chaos energy the Emeralds produce is based on thoughts. Positive thoughts, such as friendship and caring, generate positive energies and negative thoughts, such as anger and hatred, generate negative energies. If the Chaos Emeralds are either absent of their negative energies or all of their energies, they become inert and lose their lustre. The only known ways to restore them from this state is through peoples' thoughts, the Gaia Temples, or by returning their energy. The Chaos Emeralds can as well take on other powers, like when the Overmind psychically treated them into Great Emeralds which boosted their psychic powers, or potentially be enhanced.

The Chaos Emeralds amplify their own power the more of them there are used in the process. This is mainly demonstrated with the Eclipse Cannon: with five Emeralds it could destroy a large city, with six Emeralds it could blow up half of the moon and with all seven it could destroy planets and pierce stars. Like the Master Emerald, the Chaos Emeralds also appear to possess some form of sentience, like when they remained stable in spite of the conditions in an attempt to help Sonic and Tails get home from Blaze's world. Supposedly, this sentience also explains the Emeralds' tendency to show up where they are most needed.

As demonstrated on a few occasions, the Chaos Emeralds are not indestructible, and can be shattered into Emerald Shards that retain the Chaos Emeralds' chaos energy. However, like the Master Emerald, they can easily be repaired if all their shards are brought back together again.

Each Chaos Emerald is linked to each other and act like magnets that can attract each other. This for example allowed Tails to pinpoint Dr. Eggman's location on Space Colony ARK because he had the rest of the Chaos Emeralds in his possession. The Chaos Emeralds are likewise linked to the Sol Emeralds, their inter-dimensional counterparts from Blaze's world, with the two sets of Emeralds having been described as the North and South on a magnet. This makes both sets of Emeralds capable of attracting and repelling each other. Also, when in close proximity, the two sets of Emeralds call out to each other, which will generate power of cataclysmic proportions unless those wielding the Emeralds knows how to use them or the Emeralds wills themselves to remain stable.

After using all seven Chaos Emeralds, they will usually scatter themselves, meaning that they can only be used for one purpose together before disappearing again. While they can end up anywhere in the world, they quite often end up in Special Stages, which are strange alternate dimensions.

Background
The Chaos Emeralds' background is shrouded in mystery and no one knows where they come from. They have been around for several millennia, even predating the Master Emerald which has existed since before recorded time, and have played a large role in numerous events. The Chaos Emeralds' power has been passed down into legend, and the power of all seven brought together has been described from the emergence of a mysterious power to no less than a miracle.

Throughout history, civilizations have sought to harness the Chaos Emeralds' power: according to legend, the ancient civilization on West Side Island used the Chaos Emeralds for the advancement of their society and achieved great prosperity. Other civilizations that knew about the Emeralds included the Babylonians and the Black Arms, the latter who have visited Earth for at least 2,000 years. The Emeralds also have a connection to the Gaia Temples which are more or less than ten thousands of years old. There are as well numerous locations that are said to have held the Chaos Emeralds at one point (some of which claim to have done so since ancient times), including Cocoa Island, Angel Island, Flicky Island, West Side Island, and South Island. It is unknown how valid these legends are, given how some contradict others regarding the Emeralds' resting place, although this might be due to the Emeralds' tendency to appear wherever they are needed.

It is said that in the far ancient past, the Chaos Emeralds would be used for evil purposes. One such instance was when West Side Island's prosperity lead to avarice over the course of a single night when some people wanted the Emeralds for evil, sparking a conflict so great that the gods had to intervene and seal the Chaos Emeralds on the island. Witnessing this misuse, the gods created the Master Emerald to balance out the Chaos Emeralds' power and equipped the gem with the ability to nullify and control them. An ancient mantra associated with the Emeralds would eventually arise, explaining their connection and abilities.

Over 4,000 years ago, the Chaos Emeralds and the Master Emerald resided in the Altar of the Emeralds, a shrine in the outskirts of the Mystic Ruins. There, each Emerald rested on one of seven stone pillars that surrounded the Master Emerald which lay in the center of the altar. Back then, the Emeralds were known only as "the Seven Emeralds" that could grant wishes. In that shrine resided a colony of Chao. These peaceful creatures and their shrine were protected by the water-based deity Chaos, the guardian god of the Chao.

Around 4,000 years ago, ancient echidna civilizations knew of the Chaos Emeralds and sought their secrets. The Nocturnus Clan were known to have been experimenting with the Chaos Emeralds as a part of the creation of the Gizoid, while the Knuckles Clan revered the Chaos Emeralds as sacred objects. Around this time, Tikal, the daughter of chief Pachacamac of the Knuckles Clan and a friend to the Chao and Chaos, was allowed into the shrine where she could behold the Chaos Emeralds.

As the Knuckles Clan faced extermination at the hands of the Nocturnus Clan, chief Pachacamac and his followers launched a raid on the altar to take the Emeralds and gain undisputed power. Tikal stood between them however, begging her people to leave the creatures and the Emeralds alone. However, her pleas fell on deaf ears, and the men trampled over Tikal and the Chao alike in the process, prompting Chaos to appear. In a fit of rage over the harm brought to its friends, it used the Chaos Emeralds to become Perfect Chaos and wiped out the clan's civilization in vengeance, before it was sealed in the Master Emerald by Tikal. After this event, the Emeralds went missing and were dubbed the "Chaos Emeralds" due to their association with Chaos.

Over fifty years prior to Shadow the Hedgehog, the Chaos Emeralds were researched by Prof. Gerald Robotnik onboard Space Colony ARK as a part of Project Shadow. These research results led to the creation of the Chaos Drives, small capsules containing chaos energy. During the experimentations on the Chaos Emeralds, Prof. Gerald also discovered that the Gizoid he had discovered reacted to the Emeralds. After a Chaos Emerald got installed into the Gizoid however, the robot went on a rampage that destroyed most of the ARK before it was subdued.

Sonic the Hedgehog (16-bit)


In the original Sonic the Hedgehog, the Chaos Emeralds were lying dormant within distortions created on South Island, an island that moves around on the sea. However, no one knew how to obtain them. Seeking the Emeralds, presumably for research into nuclear power and various laser-based weaponry for conquering the world, Dr. Robotnik came to South Island with his gang, determined to dig up the entire island in his search for the Chaos Emeralds. However, Robotnik's nemesis, Sonic the Hedgehog, ended up obtaining the Emeralds first. After foiling Robotnik's operations, Sonic brought the Chaos Emeralds to Green Hill Zone. There, the Emeralds started to hover and rotate in the mid-air. After that, the Emeralds disappeared in a flash, with new kinds of flowers having appeared around the Green Hill Zone, although Sonic was initially baffled by this event.

In this game, there are only six Chaos Emeralds, each one in a different color: yellow, pink, blue, green, red and white. In terms of design, they are shaped like octagons (from the 2D viewpoint of the player) with a flat octagon-shaped top facet.

In gameplay, the player will obtain a Chaos Emerald whenever they clear one of the game's six Special Zones. After getting the six Chaos Emeralds and beating the final boss, the player gets the good ending of the game. In the bad ending (which the player receives if they do not get all six Chaos Emeralds), after the credits sequence, Robotnik is seen throwing Chaos Emeralds around in his hands with the words "Try Again" written below. The Emeralds Robotnik is seen throwing around in that scene depends on which Chaos Emeralds the player was not able to get before the ending.

Sonic the Hedgehog (8-bit)


In the 8-bit version of Sonic the Hedgehog, the Chaos Emeralds lay dormant on South Island. Seeking the Emeralds, presumably for research into nuclear power and various laser-based weaponry for conquering the world, Dr. Robotnik came to South Island to find them. However, Robotnik's nemesis, Sonic the Hedgehog, ended up obtaining the Emeralds first. After defeating Robotnik when he tried to escape, Sonic was trekking through Green Hill when the Chaos Emeralds started to glow in his hands before flying into the sky. There, they circled around South island and disposed of the pollutant above the island caused by the Scrap Brain Zone before vanishing.

In this game, there are only six Chaos Emeralds. Also, instead of each Emerald being a different color, they are all light blue due to hardware limitations. In terms of design, they are shaped like octagons (from the 2D viewpoint of the player) with a flat octagon-shaped top facet.

In gameplay, the Chaos Emeralds are not found inside the game's different Bonus Stages, but are instead scattered in certain Acts of each zone. Each zone holds one Emerald. Each Emerald is also worth 20,000 points at the end of the game score tally. If the player collects all six Chaos Emeralds, they will receive the game's real ending after defeating the final boss of the game.

Sonic the Hedgehog 2 (16-bit)
In the 16-bit version of Sonic the Hedgehog 2, the Chaos Emeralds resided on West Side Island, an island whose civilization had used the Chaos Emeralds in ancient times to achieve great prosperity, only for the Emeralds to cause the civilization's downfall over a single night when they were used for evil, forcing the gods to seal the Emeralds on the island. After following Sonic to West Side Island, Dr. Robotnik had his Badniks dig all over the island for the Chaos Emeralds, which he planed to use to complete his ultimate weapon: the Death Egg. However, Sonic (and his new sidekick Tails) managed to get the Chaos Emeralds first. Later, after making it onboard the Death Egg and causing it to self-destruct, Sonic used the Chaos Emeralds to become Super Sonic and fly to safety as the Death Egg exploded.

In this game, there are seven Chaos Emeralds in total, a number of which would be used by the majority of the subsequent Sonic games. However, compared to how they looked in Sonic the Hedgehog, the Emeralds are slightly different this time around: they are now hexagon-shaped rather than octagon-shaped (from the 2D viewpoint of the player), with a flat hexagon-shaped top facet. The Emeralds also each have a different color: yellow, pink, light blue, green, red, white and purple.

In gameplay, the playable character will obtain a Chaos Emerald whenever the player clears one of the game's seven Special Stages. However, the Emeralds are not shared between the characters, meaning that each character will have to attain their own set of seven Chaos Emeralds in their gameplay. After collecting all seven Chaos Emeralds as Sonic, Sonic will be able to turn into Super Sonic (who has been featured in many games since then) in regular Zones. Collecting all the Emeralds will unlock the good ending(s) of the game as well.

If the game is locked on to Sonic & Knuckles (thereby forming Knuckles the Echidna in Sonic the Hedgehog 2), Knuckles can turn into Super Knuckles in regular Zones after getting all the Chaos Emeralds as well.

Sonic the Hedgehog 2 (8-bit)
In the 8-bit version of Sonic the Hedgehog 2, the Chaos Emeralds were located on South Island. After learning that Tails had been kidnapped by Dr. Robotnik and brought to a place called Crystal Egg, which could only be entered using the Chaos Emeralds, Sonic set out to find the Chaos Emeralds and rescue Tails. Eventually, Sonic retrieved the Chaos Emeralds, the last of which was in the possession of Silver Sonic, thus allowing him to enter the Crystal Egg Zone and rescue Tails after defeating Robotnik.

In this game, there are only six Chaos Emeralds, each one in a different color: blue, yellow, purple, white, red and green. In terms of design, they are shaped like octagons (from the 2D viewpoint of the player) with a flat octagon-shaped top facet.

In gameplay, the Chaos Emeralds are not found in some kind of extra Zone. Instead, they are hidden in the regular Zones, like in the 8-bit version of Sonic the Hedgehog. Finding them can be tricky, however, as they are usually lying around on some remote, isolated platform that requires careful maneuvering to reach. There is one Chaos Emerald in each of the first five Zones, and the sixth is won after defeating Silver Sonic. For each Emerald collected, the player is rewarded with a Continue. Collecting all six Emeralds allows the player access to Crystal Egg Zone; clearing it will reward the player with the real ending of the game. If the player does not have all the Emeralds after defeating Silver Sonic, however, the game ends here and the player receives the game's bad ending.

Sonic Chaos
In Sonic Chaos, the Chaos Emeralds rested on South Island, which was able to stay afloat on the sea thanks to the Emeralds' power. Setting his sights on the Chaos Emeralds once more, Dr. Robotnik managed to steal one of them. As a result of Robotnik's tampering however, the remaining Chaos Emeralds got scattered, causing South Island to slowly sink into the sea. To save the island, Sonic and Tails set out to recover the Chaos Emeralds. After many troubles, the heroic duo managed to recover all the scattered Chaos Emeralds. Then, after defeating Robotnik, Sonic collected the Emerald Robotnik had stolen when the mad scientist dropped it during his escape.

In this game, there are only six Chaos Emeralds, each one in a different color: red, yellow, blue, green, white and gray. In terms of design, they are shaped like octagons (from the 2D viewpoint of the player) with a flat square-shaped top facet.

In gameplay, five of the Chaos Emeralds can be found in the Special Stages. However, only Sonic can enter the Special Stages and get the Emeralds. Once inside a Special Stage, the player must find and collect the Chaos Emerald that is hidden within the stage. The sixth and final Chaos Emerald is obtained after defeating the Laser Walker in Electric Egg Zone, but only if the player has obtained the other five Chaos Emeralds before-handed. Collecting all six Emeralds will unlock the game's good ending. Fail to collect all the Emeralds, and the game's bad ending will appear after clearing the final boss.

Sonic the Hedgehog Spinball


In both the 16-bit and 8-bit version of Sonic the Hedgehog Spinball, Dr. Robotnik used several Chaos Emeralds to stabilize the Mt. Mobius volcano on which his Veg-O-Fortress stood; without the Emeralds, the volcano would erupt and destroy the Veg-O-Fortress. Seeking to bring down the Veg-O-Fortress and end its robotizating operations, Sonic ventured through Mt. Mobius and collected all the Emeralds, thus ensuring the Veg-O-Fortress's demise.

In both the 16-bit and 8-bit version of Sonic the Hedgehog Spinball, the Chaos Emeralds are all blue. Like in Sonic the Hedgehog 2, the Emeralds are also hexagon-shaped (from the 2D viewpoint of the player), with a flat hexagon-shaped top facet. Both versions of the game also feature a total of sixteen Chaos Emeralds. The reason for the large number of Emeralds that appear and their uniform blue coloration are not explained. However, because both Sonic the Hedgehog Spinball titles use elements from Archie Comics' Sonic the Hedgehog comic series, it might be possible that the games' Chaos Emeralds were inspired by the comic's interpretation of the Chaos Emeralds, which were incredibly numerous and all green-colored back in the old days.

In gameplay om both versions of the game, the Chaos Emeralds are scattered around each level: three Emeralds are hidden in Level 1 and 2, and five Emeralds are hidden in Level 3 and 4. It is the player's objective to find every Chaos Emerald in each level, which requires doing certain precision pinball tricks. Obtaining a Chaos Emerald will award the player with 500.000 points. Once all Emeralds in a level have been found, the player can enter the arena where the level's boss can be fought.

Sonic the Hedgehog 3
In Sonic the Hedgehog 3, it is stated that the Chaos Emeralds were residing on Angel Island prior to the ending of Sonic the Hedgehog 2. There, they were guarded by Knuckles the Echidna, the guardian of Angel Island and the Master Emerald. The Emeralds were also said to control the power of the "pillar" in the depths of Angel Island. On the day the Death Egg crashed into Angel Island (due to Sonic's actions) however, the Chaos Emeralds suddenly flashed and began vibrating more and more abnormally. As the vibrations reached their climax, the Chaos Emeralds gave off a loud flash and disappeared, just as the Death Egg hit Angel Island. Days later, Sonic and Tails arrived at Angel Island, with the seven Chaos Emeralds in their possession, to investigate the situation. As they neared Angel Island, Sonic used the Emeralds to enter his Super State and stormed the island. However, on the island, Knuckles, who had been tricked by Robotnik into believing that Sonic was a thief out to steal the Master Emerald, ambushed Super Sonic and made him lose all seven Chaos Emeralds, which Knuckles then stole and hid away around the island. Retrieving the Chaos Emeralds, Sonic eventually used them to turn into Super Sonic after making the Death Egg crash again when it tried to take off.

In this game, the Chaos Emeralds were "finalized" as seven brilliant cut gemstones in the following colors: red, green, blue, turquoise, purple, yellow, and white. This design would be use consistently in later games.

In gameplay, the playable character will obtain a Chaos Emerald whenever the player clears one of the game's seven Special Stages. However, the Emeralds are not shared between the characters, meaning that each character will have to attain their own set of seven Chaos Emeralds in their gameplay. After collecting all seven Chaos Emeralds as Sonic, Sonic can turn into Super Sonic in regular Zones. Collecting all of the Emeralds will also unlock the good ending(s) of the game. If the player fails to get all the Emeralds, they get the game's bad ending. Also, after the credits sequence in the bad ending, Knuckles is seen throwing Chaos Emeralds up and down in his hand with the words "Try Again" written below. The Emeralds Knuckles is seen throwing around in that scene depends on which Chaos Emeralds the player was not able to get before the ending.

By locking Sonic the Hedgehog 3 onto Sonic & Knuckles, the player can play Sonic the Hedgehog 3 & Knuckles. In this game, the player can upgrade the Chaos Emeralds to Super Emeralds. To do this, the player has to enter any Sonic & Knuckles Zone with all seven Chaos Emeralds, and jump into a flashing Super Ring. These transport the character to the Hidden Palace Zone, where the Chaos Emeralds are turned into gray Super Emeralds. The player can then jump onto one of these Super Emeralds to enter a Special Stage where they can earn Super Emeralds. After this sequence, the player is unable to use their Super State again, but is able to still complete The Doomsday Zone and finish the game with just the Chaos Emeralds. Earning all Super Emeralds lets Sonic turn into Hyper Sonic, Tails into Super Tails, and Knuckles into Hyper Knuckles.

Sonic & Knuckles
In Sonic & Knuckles, both Sonic and Knuckles would hunt the Chaos Emeralds yet again. When Dr. Robotnik tried making his escape with the Master Emerald after his Great Eggman Robo was defeated by Sonic and Tails, Sonic used the Chaos Emeralds he had collected before-handed to turn into Super Sonic and pursue Robotnik into space where he defeated the doctor and retrieved the Master Emerald. Knuckles would later collect the Chaos Emeralds during his hunt for an Eggrobo that stole the Master Emerald. When the Master Emerald stood to be lost when Sky Sanctuary Zone collapsed, Knuckles used the Chaos Emeralds to become Super Knuckles, which allowed him to retrieve the Master Emerald while Sonic swooped in in the Tornado and rescued Knuckles.

In gameplay, the playable character will obtain a Chaos Emerald whenever the player clears one of the game's seven Special Stages. However, the Emeralds are not shared between the characters, meaning that each character will have to attain their own set of seven Chaos Emeralds in their gameplay. After collecting all seven Chaos Emeralds as Sonic or Knuckles, the player can turn into Super Sonic or Super Knuckles in regular Zones. By collecting all seven Chaos Emeralds, the player will also unlock the good ending(s) of the game. In Sonic's case, collecting all seven Emeralds also allows the player to enter The Doomsday Zone after defeating the Great Eggman Robo in Death Egg Zone. If the player fails to get all the Emeralds however, they will receive the game's bad ending(s).

By locking Sonic the Hedgehog 3 onto Sonic & Knuckles, the player can play Sonic the Hedgehog 3 & Knuckles. In this game, the player can upgrade the Chaos Emeralds to Super Emeralds. To do this, the player has to enter any Sonic & Knuckles Zone with all seven Chaos Emeralds, and jump into a flashing Super Ring. These transport the character to the Hidden Palace Zone, where the Chaos Emeralds are turned into gray Super Emeralds. The player can then jump onto one of these Super Emeralds to enter a Special Stage where they can earn Super Emeralds. After this sequence, the player is unable to use their Super State again, but is able to still complete The Doomsday Zone and finish the game with just the Chaos Emeralds. Earning all Super Emeralds lets Sonic turn into Hyper Sonic, Tails into Super Tails, and Knuckles into Hyper Knuckles.

Sonic Drift
In Sonic Drift, the Chaos Emeralds make a small appearance. In this game, they denote the difficulty of the racing competitions in the game's Chaos GP. The easy races are denoted as Green, the medium-difficult as Yellow, and the hardest as Red.

In this game, the Chaos Emeralds are depicted as hexagon-shaped (from the 2D viewpoint of the player), with a flat hexagon-shaped top facet, like in Sonic the Hedgehog 2 and Sonic the Hedgehog Spinball.

Sonic Drift 2
In Sonic Drift 2, the Chaos Emeralds, like in Sonic Drift, are used to denote the difficulty of the racing competitions in the game's Chaos GP. The easy races are denoted as Purple, the medium-difficult as White, and the hardest as Blue. They are also shaped like the Chaos Emeralds depicted in Sonic Drift, making them hexagon-shaped (from the 2D viewpoint of the player), with a flat hexagon-shaped top facet.

Sonic the Hedgehog's Gameworld
In Sonic the Hedgehog's Gameworld, a Chaos Emerald was hidden on each floor of Dr. Robotnik's five-story Gameworld, an amusement park-like tower built in Robotnik's own image. Seeking the Chaos Emeralds, Sonic, Tails and Amy had to clear all the minigames on each floor to retrieve them. Making it to the roof of Gameworld, Sonic and co. got away with the Chaos Emeralds after beating Robotnik's final challenge.

In this game, only five Chaos Emeralds are seen. In terms of design, the Emeralds are hexagon-shaped (from the 2D viewpoint of the player), with a flat hexagon-shaped top facet. They also come in the following colors: white, yellow, green, red and orange.

In gameplay, the Chaos Emeralds appear in the last minigame: Diamond Race. Here, the player starts out on the rooftop and must retreat through Gameworld's four levels in a race against Robotnik to find the Chaos Emeralds hidden on each floor. Once all five Emeralds have been located, the character holding the most wins the game.

Sonic the Hedgehog Triple Trouble
In Sonic the Hedgehog Triple Trouble, Dr. Robotnik managed to collect all the Chaos Emeralds in secret. However, when Robotnik made a mistake during the testing of his ultimate weapon, an accident occurred that blew all the Chaos Emeralds away. While Robotnik managed to find one of the Emeralds, he had no clue where to find the rest. Still, he was determined to find them. Meanwhile, having learned of Robotnik's accident, Sonic and Tails set out to get the Chaos Emeralds before the doctor. At the same time, Knuckles, who had been convinced by Robotnik that Sonic wanted the Chaos Emeralds for world domination, found the Chaos Emeralds and hid them away in subspace. Also seeking the Chaos Emeralds this time was Nack the Weasel, a rogue treasure hunter. Ultimately, Sonic and Tails managed to retrieve all the scattered Chaos Emeralds. Then, when Robotnik tried to make his escape after his defeat in Atomic Destroyer Zone, Sonic and Tails robbed the doctor of the final Chaos Emerald.

In this game, there are only six Chaos Emeralds, each one in a different color: blue, red, yellow, white, orange, and light yellow. In terms of design, they are shaped like hexagons (from the 2D viewpoint of the player) with a flat hexagon-shaped top facet.

In gameplay, like in Sonic Chaos, five of the Chaos Emeralds can be found in the Special Stages. This time however, both Sonic and Tails can collect them. Once inside a Special Stage, the player must clear the Special Stage and then defeat Nack in a boss battle before they can obtain the Emerald. The sixth and final Chaos Emerald is obtained after defeating the final boss in Atomic Destroyer Zone. Collecting all six Emeralds will unlock the game's good ending. In the bad ending (which the player receives if they do not get all six Chaos Emeralds), Nack can be seen, laughing, before tripping and dropping the Chaos Emeralds when he tries to run away, with the words "Try Again" appearing on the screen afterward. The Emeralds Nack drops in that scene depends on which Chaos Emeralds the player was not able to get before the ending.

Tails Adventure
In Tails Adventure (which take place before Tails met Sonic), the Chaos Emeralds were located on Cocoa Island, an island on which the Chaos Emeralds were said to have laid dormant on since ancient times. Seeking the Chaos Emeralds for world domination, the Battle Kukku Empire, led by the Great Battle Kukku, came to Cocoa Island. Living on the island, however, was Tails, who decided to stop the Great Battle Kukku's ambitions. Over the course of his adventure, Tails found the Chaos Emeralds and benefited from their powers.

In this game, there are only six Chaos Emeralds, which are colored (in order of appearance) red, green, purple, white, blue, and yellow. Also, rather than appearing as gems, the Emeralds are depicted as blue and orange boxes.

In gameplay, the Chaos Emeralds are scattered across the levels. Obtaining a Chaos Emerald will increase Tails' maximum Ring count by ten Rings and his Flight Gauge by a few seconds. If the player have five Emeralds and procure the sixth, Tails' maximum Ring count shoots up to its maximum of ninety-nine (note that Emeralds cannot be equipped but are always active).

Sonic Labyrinth
In Sonic Labyrinth, Dr. Robotnik stole the Chaos Emeralds from South Island and used their power to craft the irremovable Slow-Down Boots which he tricked Sonic into wearing, thus stripping the hedgehog of his speed and agility. With the Chaos Emeralds in hand, Robotnik boasted across South Island that the only thing that could get the Slow-Down Boots off Sonic were the Chaos Emeralds' power. In response, Sonic headed into Robotnik's newly constructed super labyrinth to get the Chaos Emeralds. After many trials, Sonic recovered the Chaos Emeralds, the last of which he got from Robotnik himself when the mad doctor dropped it during his escape from Sonic, and regained his speed.

In this game, there are six Chaos Emeralds in total, although only five of them are seen. These five Emeralds are colored (in order of appearance) blue, red, orange, dark blue and green. Also, the first three Emeralds are depicted as semi-table cut gemstones while the last two are depicted as point cut gemstones.

In gameplay, the player will obtain a Chaos Emerald from each of the game's four bosses after defeating them. The fifth Chaos Emerald on the other hand is only obtained after the player clears the hidden Bonus Stage (although no indication of the Chaos Emerald being obtained is given). The sixth and final Chaos Emerald is obtained from Robotnik after defeating the game's final boss. Collecting all six Chaos Emeralds will unlock the game's good ending. Collect any less than that and the game's bad ending will appear instead.

Sonic the Fighters
In Sonic the Fighters, the Chaos Emeralds were being guarded separate by Sonic, Tails, Knuckles, Amy, Espio, Bark, and Bean so they could not be misused by Dr. Robotnik. However, Fang the Sniper managed to steal one of them. When the world then came under the threat of the Death Egg II, Sonic planned to use the Chaos Emeralds to power the Lunar Fox, a single-seat spaceship Tails had invented which required all the Chaos Emeralds as a power source, to go to the Death Egg II. After Sonic got into an argument with Knuckles however, it was decided that a fighting tournament was to be held to determine the most qualified fighter amongst the Chaos Emerald bearers to use the Lunar Fox. Eventually, the victor of the tournament won the Chaos Emeralds from the fighters after besting each of them in battle. This person went to the Death Egg II in the Lunar Fox and initiated its self-destruct sequence. When Robotnik then arrived to defeat the victor with the E-Mech, the victor used the Chaos Emeralds to give themselves a power boost, allowing them to defeat Robtonik and escape in the Lunar Fox before the Death Egg II exploded.

In this game, there are a total of eight Chaos Emeralds. Why an extra Emerald was added to the set and where it came from is not explained. Also, while the Emeralds retain their brilliant cut design in this game, they have received the following new colors: blue, orange, red, violet, yellow, green, purple, and pink.

In gameplay, the playable character receives a Chaos Emerald each time they defeat one of the game's first eight opponents. Later, during the final battle with Robotnik and his E-Mech, the playable character will use the Chaos Emeralds to use their Hyper Mode/super transformation.

Sonic 3D Blast


In Sonic 3D Blast, the Chaos Emeralds laid dormant on the mysterious Flicky Island, an island which legend said held the Chaos Emeralds. Serving as a clue to the gems' whereabouts were the island's strange Flickies from another dimension. Eventually discovering Flicky Island, Dr. Robotnik traveled there and discovered the Flickies' secret way of traveling between dimensions. He then began turning the Flickies into Badniks to search for the Chaos Emeralds. However, Sonic, Tails and Knuckles soon after came to Flicky Island as well to find the Chaos Emeralds too. Finding the island in pandemonium, Sonic set out to find the Chaos Emeralds before Robotnik and save the Flickies. After accomplishing his mission, Sonic used the seven Chaos Emeralds to enter Robotnik's final bastion and defeat his final weapon, thus restoring peace to Flicky Island.

In this game, there are seven Chaos Emeralds in the colors red, blue, turquoise, green, yellow, purple and white, like in Sonic the Hedgehog 3 and Sonic & Knuckles. However, their shape varies between the versions of the game. In the Sega Mega Drive version, the Emeralds are cuboid-shape with a circular depression in one of the facets. In the Sega Saturn/PC version however, they possess the brilliant cut shape they take on today.

In gameplay, the player will obtain a Chaos Emerald whenever the player clears one of the game's seven Special Stages. If the player collects all seven Chaos Emeralds, they can enter The Final Fight after clearing Panic Puppet Zone. Should the player then clear The Final Fight, they will unlock the game's good ending. In case the player fails to get all the Emeralds however, the game ends after Panic Puppet Zone and the player will receive the game's bad ending. In the bad ending on the Sega Mega Drive version, Robotnik will be shown holding the green, yellow, blue and red Chaos Emerald. In the bad ending on the Sega Saturn/PC version on the other hand, Robotnik is seen throwing Chaos Emeralds between his hand with the words "Try Again" written above. The Emeralds Robotnik is seen throwing around in that scene depends on which Chaos Emeralds the player was not able to get before the ending.

Sonic Blast


In Sonic Blast, the Chaos Emeralds rested on South Island, maintaining the island's peace. While the protector of the Emeralds, Sonic, slept in his hammock with a Chaos Emerald on hand however, Dr. Robotnik tried shooting Sonic with a laser. However, he accidently hit Sonic's Emerald instead. Awakening, Sonic saw the Chaos Emerald spin violent before shattering into five multicolored Emerald Shards which flew to all the corners of the island. Pleased with the unexpected result nonetheless, Dr. Robotnik planned to find the Chaos Emerald shards and use them to fortify his new Silver Castle. In response, Sonic and the newly-arrived Knuckles decided to team up and crush Robotnik's ambition. Ultimately, Sonic and Knuckles got the Chaos Emerald shards back and destroyed the Silver Castle.

In this game, the Chaos Emeralds are brilliant cut gemstones. The original Chaos Emerald is depicted as a multicolored gem, while its shards are depicted as smaller Chaos Emeralds in the colors red, blue, green, yellow, and white.

In gameplay, the playable character will obtain a Chaos Emerald shard whenever the player clears one of the game's five Special Stages. If the player collects all five Chaos Emerald shards and then clears Silver Castle Zone, they will access the game's final boss. Beating that boss will lead to the game's good ending, which shows the playable character tossing the Chaos Emerald shards around in their hand. If the player has not gotten all the Emeralds before clearing Silver Castle Zone however, the game will end after clearing Silver Castle Zone and the player will receive the game's bad ending.

Sonic R


In Sonic R, the Chaos Emeralds rested along the race venue of the World Grand Prix. Having discovered the Chaos Emeralds' whereabouts, Dr. Robotnik planned on obtaining them and using them for world domination. Rather than looking for them himself however, Robotnik signed up for the World Grand Prix to lure Sonic and his friends into joining the competition. He would then let Sonic and co. handle the grunt labor of hunting the Emeralds out. Once the Emeralds had been located, Robotnik planned on appropriating them with his legion of evil racing robots. Eventually, all the Chaos Emeralds were found, although they did not end up in Robotnik's hands.

In this game, the Chaos Emeralds are depicted as seven brilliant cut gemstones, like in Sonic the Hedgehog 3 and Sonic & Knuckles. However, these Emeralds are colored blue, purple, green, red, white, yellow, and orange.

In gameplay, the Chaos Emeralds are hidden on the first four race tracks, usually behind Ring Gates that require fifty Rings to be unlocked. Once the player manages to find an Emerald during a race and nab it, they must finish the race in first place to keep it. If placed second or lower, the obtained Emerald will be lost, and the player must start the procedure over. Collecting all seven Emeralds will unlock Super Sonic as a playable character.

Sonic Adventure
In Sonic Adventure and Sonic Adventure DX: Director's Cut, Dr. Eggman discovered an ancient deity called Chaos that grew bigger and stronger for each Chaos Emerald it absorbed. Seeking to use the creature to destroy Station Square and built Robotnikland upon its ruins, Eggman freed Chaos from its imprisonment in the Master Emerald and began hunting the Chaos Emeralds. However, Eggman also ended up freeing Tikal, who would show the Chaos Emeralds' past from 4000 years ago to those involved in this incident in hopes that they would understand the danger that was looming.

The purple Chaos Emerald was discovered by Tails prior to Chaos' release during one of his test fights, who used it to power a new prototype airplane. Meanwhile, the yellow Chaos Emeralds had been found by Big, who kept it as a lucky charm. Lastly, the turquoise Chaos Emerald resided in a pedant belonging to a bird that Eggman had captured.

On the night of Chaos' release, Big's friend Froggy swallowed Big's Chaos Emerald after he got possessed by Chaos by drinking Chaos' fragmented tail, before running away. Soon after, Tails crashed in his prototype airplane, leaving him and Sonic to take the purple Chaos Emerald back to Tails' workshop. Upon arrival however, Dr. Eggman came and managed to take the purple Chaos Emerald from Tails, which he then fed to Chaos 0, transforming it into Chaos 1. Afterward, Sonic and Tails decided to find the remaining Emeralds to keep Chaos from transforming any further. The duo soon after found the blue Chaos Emerald in Windy Valley and the white Chaos Emerald in Casinopolis. Upon leaving Casinopolis however, Eggman ambushed Sonic and Tails with sleeping gas and stole the white Chaos Emerald, which he later gave to Chaos 1, transforming it into Chaos 2. Undeterred, Sonic and Tails retrieved the green Chaos Emerald from Icecap. However, upon their return to Mystic Ruins, Knuckles attacked them, having been duped by Eggman into believing that Sonic and Tails were hunting the Master Emerald's scattered shards. During the fight, Sonic dropped the blue and green Chaos Emerald, which Eggman then appeared to claim and fed to Chaos 2, transforming it into Chaos 4.

As Eggman retreated in his Egg Carrier, the bird carrying the turquoise Chaos Emerald managed to escape from the Egg Carrier and ended up in Amy's care. Meanwhile, after failing to catch the Egg Carrier in the Tornado, Tails concluded that he had to finish his Tornado 2 in order to beat the Egg Carrier. To do that however, he needed a Chaos Emerald. He soon found the red Emerald, only for Froggy to nab it and run away. Eventually though, Tails caught Froggy and got the red Chaos Emerald away from him, which he then installed into his Tornado 2 as a power source. Soon after though, the bird with the turquoise Chaos Emerald ended up on the Egg Carrier again, where Eggman took its Emerald away from it. Meanwhile, Froggy, who had also been brought onboard the Egg Carrier, was rescued by Big. As they escaped however, they encountered Chaos 4 and Eggman. There, Eggman and Froggy gave their respective Chaos Emeralds to Chaos, transforming it into Chaos 6. After Chaos 6 was defeated by Knuckles however, the deity relinquished its six Chaos Emeralds, which Knuckles took with him to Angel Island.

On Angel Island, the Chaos Emeralds seemingly prevented Angel Island from taking flight. Soon after, Chaos appeared, having broken off its alliance with Eggman, and stole the six Chaos Emeralds. Learning of the theft, Sonic and Tails hurried out to find the last Chaos Emerald, which was still in the Tornado 2. Upon finding it however, Chaos took it. With all seven Emeralds in its possession, Chaos transformed into Perfect Chaos and attacked Station Square. During its rampage, Perfect Chaos drained the Chaos Emeralds of their negative chaos energy using its anger and sadness and expelled them across the ruins of Station Square. The inert Chaos Emeralds were then gathered by Sonic's friends and given to Sonic. Using the trust of his friends and those believing in him, Sonic recharged the Chaos Emeralds and used them to turn into Super Sonic. With the Emeralds' power, Sonic defeated Perfect Chaos and neutralized the anger and sadness possessing it.

In gameplay, the acquisition of the Chaos Emeralds were integrated into the mainstream story line, instead of being an objective the player had to accomplish in different levels. This was a first for the Sonic series and would start a recurring trend for several subsequent Sonic games.

Sonic the Hedgehog Pocket Adventure
In Sonic the Hedgehog Pocket Adventure, the Chaos Emeralds were being collected by Sonic. While the hedgehog was able to gather six of them from the Special Stages, the seventh (the purple one) remained in the possession of Knuckles. During a confrontation between Sonic and Knuckles, the latter dropped his Emerald. When Sonic tried returning the Chaos Emerald however, Dr. Eggman dropped in and stole it. After Sonic chased Eggman to the Last Utopia Zone, Eggman used the Emerald he stole to power his lastest weapon. However, Sonic took the Emerald back and destroyed Eggman's weapon. As Eggman then fled into space, Sonic used the Chaos Emeralds to turn into Super Sonic and defeat Eggman for good, before flying down from space and landing on the bypassing Tornado. Sonic then powered down to normal as the Chaos Emeralds scattered themselves. Afterward, Sonic got Knuckles' Chaos Emerald back to him.

In this game, the Chaos Emeralds are depicted as seven brilliant cut gemstones in the following colors: red, blue, green, yellow, purple, white and pink.

In gameplay, Sonic will obtain a Chaos Emerald whenever the player clears one of the game's six Special Stages. The seven Emerald, however, can only be obtained during Last Utopia Zone's boss battle. To acquire that Chaos Emerald, the player must physically hit the Emerald that sits on the back of the boss instead of the boss's cockpit until it is knocked loose. The player must then collect the Emerald and destroy the boss. However, if the player destroys the boss first, the Chaos Emerald will be lost. Collecting all seven Chaos Emeralds will let the player enter Chaotic Space Zone after clearing Last Utopia Zone and let them see the game's good ending after defeating the final boss. If the player misses any of the seven Emeralds however, the game ends after Last Utopia Zone and the bad ending will appear.

Sonic Adventure 2
In Sonic Adventure 2 and Sonic Adventure 2: Battle, the Chaos Emeralds played another central role. This time around, Dr. Eggman had managed to get the white Chaos Emerald, while Rouge the Bat had obtained the blue Chaos Emerald. Meanwhile, the yellow Chaos Emerald, which had become the famed prize of Station Square, was given to Tails as a reward for the fox's heroic deed when he saved the city from Eggman's missile attack. The red, purple and turquoise Chaos Emeralds on the other hand were put in the cargo area on Prison Island while the green Chaos Emerald was kept in the national reserve bank.

During his break-in on Prison Island, Eggman used the white Chaos Emerald to awaken Shadow the Hedgehog from his stasis. After disposing of a B-3x Hot Shot and instructing Eggman to bring more Chaos Emeralds to the Space Colony ARK, Shadow broke into the national reserve bank and stole the green Chaos Emerald. While escaping the military and the police, Shadow used his Emerald to demonstrate his Chaos Control ability when he came across Sonic. Reuniting with Eggman onboard the ARK, Shadow showed the doctor the Eclipse Cannon, a weapon capable of destroying a planet, by booting it up with his green Chaos Emerald. To reactivate it and use it to its full potential however, all seven Chaos Emeralds were needed to power it. With such a weapon, Eggman planned to force the world's leaders into surrendering to the Eggman Empire. Rouge soon after showed up and offered both her blue Chaos Emerald and her services to Eggman (all so she could secretly infiltrate Eggman's ranks on behalf of the government), which Eggman and Shadow accepted.

The three Chaos Emeralds on Prison Island were later stolen from their containers by Rouge on behalf of Eggman. However, when the island was set to blow up, Rouge got trapped inside a locked safe with the Emeralds. Fortunately, Shadow came and warped him, her, and the Emeralds to safety with Chaos Control. Having now six Chaos Emeralds, the Emeralds got inserted into the Eclipse Cannon which Eggman used to blow half of the moon up as a demonstration of power to the world. When Sonic, Tails, Amy and Knuckles then arrived on the ARK to stop Eggman, Tails revealed a fake Emerald he had made after researching the real one. This gem possessed a Chaos Emerald's properties and appearance, but was weaker in terms of power and could reverse the energy field inside the real Chaos Emeralds and then explode. Sonic and co. thus planned to insert the fake Emerald into the Eclipse Cannon and destroy it. However, that planned failed, and Tails and Eggman ultimately fought each other. Although Eggman was defeated, he secretly stole the yellow Chaos Emerald from Tails and escaped.

In the end, Eggman placed the last Chaos Emerald in the Eclipse Cannon. Upon doing so however, he triggered the doomsday program made by his late grandfather, Gerald Robotnik (which was Shadow's plan all along). This program, which Gerald had created to avenge his granddaughter Maria's death at the hands of GUN, pulled the Chaos Emeralds into the Cannon's Core where their energy was used to turn the core into a reactive bomb and shift the ARK's position so that it would collide with Earth; if the ARK collided with the Earth, the planet would be destroyed. Sonic, his friends, Eggman and Rouge thus teamed up to reach the core and cut off the Chaos Emeralds' energy with the Master Emerald, which Knuckles had on him. In the core, Knuckles successfully shut down the Chaos Emeralds with the Master Emerald. However, the ARK was kept on its collision course by the Finalhazard. In response, Sonic and a reformed Shadow used the Chaos Emeralds to turn into Super Sonic and Super Shadow. Together, the two superpowered hedgehogs destroyed the Finalhazard and returned the ARK to orbit with a massive Chaos Control.

In gameplay, the acquisition of the Chaos Emeralds were integrated into the mainstream story line, instead of being an objective the player had to accomplish in different levels. Also, in Security Hall, the player's objective is to find the red, purple and turquoise Emerald within a time limit.

Sonic Advance
In Sonic Advance, Dr. Eggman sat his sights on the Chaos Emeralds once again as he began his lastest scheme to expand his Eggman Empire. Jumping into action to stop Eggman, Sonic, Tails, Knuckles and Amy collected the Chaos Emeralds before Eggman. When Dr. Eggman later retreated to the moon after being defeated in X-Zone, Sonic used the Chaos Emeralds to turn into Super Sonic and defeated Eggman and his Super Egg Robot in a final showdown on the moon's surface. Several days later, Super Sonic showed up in the sky.

In gameplay, the playable character will obtain a Chaos Emerald whenever the player clears one of the game's seven Special Stages. Additionally, the collected Chaos Emeralds are shared among the cast of playable characters, meaning that every Chaos Emerald only needs to be collected once. After collecting all the Chaos Emeralds, the player will be able to access The Moon Zone as Super Sonic after defeating the EGG X in X-Zone as Sonic, and by clearing it, the player will be treated to the true ending of the game. If the player fails to get all the Chaos Emeralds however, the game ends after X-Zone and the player will see the game's bad ending.

Sonic Advance 2
In Sonic Advance 2, the Chaos Emeralds were collected by Sonic and his pals once more. When Vanilla, the mother of Cream, later got kidnapped by Dr. Eggman in his latest machine, Sonic used the Chaos Emeralds to turn into Super Sonic and pursued Eggman into space where he defeated Eggman and rescued Vanilla.

In gameplay, the playable character will obtain a Chaos Emerald whenever the player clears one of the game's seven Special Stages. However, the Emeralds are not shared between the characters, meaning that each character will have to attain their own set of seven Chaos Emeralds in their gameplay. If the player collects all seven Chaos Emeralds with any character, the Tiny Chao Garden feature and Boss mode of Time Attack are unlocked. If Sonic collects all seven Chaos Emeralds, the player can access True Area 53 from the Zone Select and progress to the true ending of the game. Also, if Sonic, Tails, Knuckles and Cream each collect the seven Chaos Emeralds, Amy is unlocked as a playable character.

Sonic Advance 3
In Sonic Advance 3, the Chaos Emeralds were acquired by Dr. Eggman, who used them to induce a Chaos Control that divided the world into seven parts, which the doctor then planned to turn into an Eggman Empire each. Afterward, the Emeralds ended up in the Special Stages again. To restore the world, Sonic and his friends sought to collect the Chaos Emeralds and undo Eggman's mischief with Chaos Control. After obtaining the Emeralds, Sonic and co. defeated Dr. Eggman and his new enforcer G-merl at the Altar Emerald. As the villains made their escape however, G-merl sensed the Chaos Emeralds in Sonic's possession and attacked him, causing him to drop the Emeralds. G-merl then used the Chaos Emeralds to turn into Ultimate G-merl, before rebelling against Eggman and fleeing. However, Sonic used the Chaos Emeralds left behind by Ultimate G-merl to turn into Super Sonic and, with the help of Dr. Eggman, defeated Ultimate G-merl.

In gameplay, the playable character will obtain a Chaos Emerald whenever the player clears one of the game's seven Special Stages. Additionally, the collected Chaos Emeralds are shared among the cast of playable characters, meaning that every Chaos Emerald only needs to be collected once. Once a Chaos Emerald has been obtained, the player can go see it in its associated Zone's Chao Playground. Collecting all the Chaos Emeralds lets the player access Nonaggression as Super Sonic after defeating the Hyper Eggrobo in Altar Emerald as Sonic, and by clearing it, the player will receive the true ending of the game. If the player fails to get all the Chaos Emeralds however, the game ends after beating the Hyper Eggrobo and the player will receive the alternate ending.

Sonic Heroes
In Sonic Heroes, the Chaos Emeralds were collected by Team Sonic, Team Dark, Team Rose and Team Chaotix: Team Sonic found the blue Chaos Emerald, Team Dark obtained the green and white Chaos Emerald, Team Rose collected the yellow and purple Chaos Emeralds, and Team Chaotix gathered the red and turquoise Chaos Emeralds. All the Emeralds were eventually given to Team Sonic, so they could take down a rogue Metal Sonic. After Metal Sonic assumed his ultimate form, Metal Overlord, Sonic used the Chaos Emeralds to turn into Super Sonic while passing his power onto Tails and Knuckles, turning them into Super Tails and Super Knuckles. Together, the trio of Super State users defeated Metal Overlord.

In gameplay, the playable character will obtain a Chaos Emerald whenever the player clears one of the game's seven Special Stages that feature the "Emerald Challenge". Additionally, the collected Chaos Emeralds are shared among the cast of playable characters, meaning that every Chaos Emerald only needs to be collected once. By collecting all seven Chaos Emeralds, the player will unlock the Last Story, which is the game's epilogue. Each Chaos Emerald is collected in the following color order: green, blue, yellow, gray, turquoise, purple, and red. Also, when using Chaos Inferno, Shadow will pull out the green Chaos Emerald and use Chaos Control as a part of the Team Blast. How Shadow obtained the Chaos Emerald is not explained.

Sonic Battle
In Sonic Battle, four of the Chaos Emeralds were found by Dr. Eggman, who used them to experiment on robot cores. Three of these Emeralds were eventually crushed into five Emerald Shards each by Eggman and used to power his new E-121 Phi units, which he programmed to hunt down all seven Emeralds. One of the other Chaos Emeralds ended up in Knuckles' possession, while another one was being held by Shadow. The last one resided in a jewelry shop in Emerald Town.

Eggman soon gave his last Chaos Emerald to the Gizoid he had found: Emerl, a Gizoid powered by Chaos Emeralds. However, after refusing to fight, Eggman threw Emerl out when he would not give him the Emerald back. When Rouge later met Eggman and one of his Phis, Rouge destroyed the latter and took its Chaos Emerald shard. She later obtained another Chaos Emerald shard from the tenth Phi unit under unknown circumstances.

Emerl was soon after found by Sonic, and with Tails' aid, he discovered that Emerl grew with each Chaos Emerald inserted into him. Wanting to help Emerl grow, Sonic and Tails took him to Knuckles and convinced him to let them borrow his Chaos Emerald, which they inserted into Emerl. Not long after, Tails learned that Emerl was a superweapon. However, the heroes discovered that by inserting all seven Chaos Emeralds into Emerl, they could reset him with some keywords and turn him into an ordinary robot, making their hunt for the Emeralds all the more important.

The Chaos Emerald in Emerald Town was soon after stolen by Rouge and Emerl (whom she had gotten a hold of). However, once Rouge got the Emerald, Emerl took it and absorbed it. Four Chaos Emerald shards were subsequently retrieved from four Phis by Knuckles and Emerl. After receiving one of Rouge's shards as well, Knuckles and Emerl were able to reassemble the shards into a whole Chaos Emerald with Tails' aid, which Emerl then received. When Amy and Emerl later teamed up, the duo would destroy four Phis and claim their Chaos Emerald shards. After they obtained the fifth shard from Rouge, Amy and Emerl had Tails put them together, and Emerl promptly received his fifth Chaos Emerald. When they later got trapped in the Gimme Shelter, Cream and Emerl gathered four Chaos Emerald shards from the residential Phis. The fifth shard, which Chaos Gamma held to boost his power, was eventually claimed as well. The shards were then put together and Emerl absorbed the reassembled Chaos Emerald. The last Chaos Emerald was later willingly given to Emerl by Shadow himself after he learned of Gerald Robotnik's intentions for Emerl. With all seven Chaos Emeralds in him, Emerl's true nature awoke until Shadow reset him with Gerald's secret keywords.

Eventually, Eggman accidently made Emerl go berserk when he tried to take control of him. To keep Emerl from destroying the world with the Final Egg Blaster, Sonic tried using the Master Emerald to stop the Chaos Emeralds from getting out of control and snap Emerl back to his senses. However, the Master Emerald got shattered before Sonic could stop the Chaos Emeralds. having no other choice, Sonic damaged Emerl until he self-destructed. The Chaos Emeralds were then released, partially or entirely in the form of shards. To calm a heartbroken Cream, Sonic assured her that Emerl was with them in the Emerald shards.

In this game, all seven Chaos Emeralds are depicted as green brilliant cut gemstones. However, from the in-game perspective, they are stated to be in different colors. In gameplay, the acquisition of the Chaos Emeralds were integrated into the mainstream story line instead of being an objective the player had to accomplish in different levels. Also, upon obtaining a Chaos Emeralds, Emerl's Skill Points will increase by ten.

Sega Superstars
In Sega Superstars, the Chaos Emeralds appear along the route in the Sonic's Speed Chute minigame, which features Sonic or Shadow running down a Special Stage-like tunnel filled with Rings and spiked bombs. During the minigame, the player can collect the Emeralds. Whenever a Chaos Emerald is getting near, a indicator will appear that shows where the Chaos Emerald is located. Collecting all seven Chaos Emeralds will transform Sonic or Shadow into Super Sonic or Super Shadow for the remainder of the minigame.

Sega Superstars Tennis
In Sega Superstars Tennis, the Chaos Emeralds are seen when Sonic transforms into Super Sonic and Shadow transforms into Super Shadow as a part of their Superstar State.

In the Xbox 360/PlayStation 3 version of the game, the Chaos Emeralds are used in the mission, "Chaos Emerald Dash" of the Sonic the Hedgehog series. In the said mission, the player has to collect five of the Chaos Emeralds in forty-five seconds, though the player can also collect all the seven Chaos Emeralds for a higher Rank in the mission.

Sonic & Sega All-Stars Racing
In Sonic & Sega All-Stars Racing, the Chaos Emeralds are seen when Sonic transforms into Super Sonic and Shadow transforms into Super Shadow as a part of their All-Star Moves. The icon for these moves also has a picture of all the Chaos Emeralds.

Sonic Jump
In Sonic Jump, Dr. Eggman began gathering the Chaos Emeralds for the purpose of using them to power a Brainwash Beam that would let him take control of the world. After gathering six of the Chaos Emeralds, the doctor went to Angel Island to get the last one from Knuckles. There, Eggman took the Emerald while Knuckles was distracted. After making it to his space satellite where the Brainwash Beam was with all seven Emeralds however, Sonic arrived and made the space satellite explode, causing the Chaos Emeralds to be scattered across Earth. Afterward, the Emeralds were retrieved by Sonic, include the one Eggman managed to keep his mitts on.

In this game, the Chaos Emeralds are depicted as seven brilliant cut gemstones in the following colors: red, green, blue, black, purple, yellow, and white.

In gameplay, the player must complete an Act with at least fifty Rings in their possession in order to obtain a fragment of a Chaos Emerald. Completing all three Acts of a Zone will complete its associated Chaos Emerald. If the player manages to collect the first six Chaos Emeralds, they will unlock the Bonus Zone where the final Chaos Emerald can be earned.

Shadow the Hedgehog
In Shadow the Hedgehog, the Chaos Emeralds became the driving force in a three-way war between the Eggman Empire, GUN, and an extraterrestrial race of evil aliens known as the Black Arms. At the beginning of the war, Black Doom, the leader of the Black Arms, instructed Shadow to bring him the seven Chaos Emeralds which he needed to begin the ritual of prosperity. Shadow himself accepted the hunt for the Emeralds, believing he could uncover the secrets of his past that way.

After a long journey and many moral choices, Shadow obtained all seven Chaos Emeralds. Arriving afterward on the Black Arms' home, the Black Comet, Shadow met Black Doom, who asked for the Chaos Emeralds. However, as Sonic and his allies arrived to stop Shadow from handing the Chaos Emeralds over, Black Doom took the Emeralds himself and used them to perform a superpowered Chaos Control that brought the Black Comet down to Earth, allowing him to commence with the ritual of prosperity. The Chaos Emeralds were then taken to the heart of the Black Comet by Black Doom when Shadow decided to stop Black Doom's plans. There, Black Doom left the Chaos Emeralds behind when he warped away to prepare for his battle with Shadow. Shadow then used the abandoned Emeralds to transform into Super Shadow. With the Emeralds' power at his disposal, Super Shadow defeated Devil Doom (the enhanced form of Black Doom) and sent the Black Comet back into space with Chaos Control where it was destroyed by the Space Colony ARK's Eclipse Cannon.

In this game, the Chaos Emeralds are depicted as seven brilliant cut gemstones in the following colors: red, green, blue, turquoise, purple, yellow, and white. However, they are brighter in cutscenes, while in gameplay, they are darker. They are also bigger.

In gameplay, Shadow will usually obtain a Chaos Emerald after he clears a certain mission in a given stage or defeats a specific boss. One Chaos Emerald in a certain scenario is also obtained during a cutscene. Also, in Westopolis, the green Chaos Emerald is obtained in mid-level. Regardless, before entering one of the five final stages in the game, the player will always have collected five Chaos Emeralds. The sixth is gained after passing the final stage, and the seventh is obtained after beating one of the three final bosses. At the end of every scenario, the Chaos Emeralds will revolve around Shadow, who will then state who he is.

Sonic Rush
In Sonic Rush, the Chaos Emeralds were collected by Sonic. Coming to the aid of the defeated Blaze, Sonic taught her how to use the Sol Emeralds, the inter-dimensional counterparts of the Chaos Emeralds from Blaze's world, causing them to be recharged after being drained of their power. Sonic then used the Chaos Emeralds to turn into Super Sonic while Blaze used the Sol Emeralds to become Burning Blaze, and together, the two heroes defeated Dr. Eggman and Dr. Eggman Nega's Egg Salamander and restored their universes.

In gameplay, Sonic will obtain a Chaos Emerald whenever the player clears one of the game's seven Special Stages. If the player collects all seven Chaos Emeralds, along with all seven Sol Emeralds, they will unlock the game's Extra scenario, which features the true epilogue of Sonic Rush.

Sonic Rush Adventure
In Sonic Rush Adventure, the Chaos Emeralds somehow ended up in Blaze's world, where they were collected by Sonic, who was stranded in Blaze's world with Tails. Eventually, Tails began working on a device that would let him and Sonic use the Emeralds' power to get them back to their dimension. Suddenly, however, Dr. Eggman and Dr. Eggman Nega appeared to harness the Power of the Stars with the Jeweled Scepter and their Egg Wizard. To stop the Eggmen, Sonic used the Chaos Emeralds to become Super Sonic while Blaze used the Sol Emeralds to become Burning Blaze. Together, the two heroes defeated the Eggmen and destroyed their Egg Wizard. Afterward, Tails created the SS Tornado EX, a vehicle that used the power of both the Chaos Emeralds and Sol Emeralds to travel between dimensions, for him and Sonic to go home in. Curiously, both sets of Emeralds were extremely stable while Tails made it instead of causing cataclysmic effects. This made Tails conclude that the Emeralds seemingly wanted to help Sonic and Tails go home. As Sonic then prepared to head home, Blaze suggested that his and Tails' surprise arrival in her world was caused by the Emeralds.

In gameplay, the player will be awarded with a Chaos Emerald each time they come out victorious from one of Johnny's seven races. If the player collects all seven Chaos Emeralds, along with all seven Sol Emeralds, they will unlock the game's epilogue and final stage.

Sonic Riders
In Sonic Riders, the Chaos Emeralds were being hunted once again. One factions of the Emerald hunters were the Babylon Rogues, who worked with Dr. Eggman to gather all seven Chaos Emeralds and use them to find Babylon Garden. The other faction tracking the Emeralds was Team Sonic, who used an Emerald Detector to find them. One Emerald, which lay in Future City, was eventually stolen by the Babylon Rogues. Team Sonic tried to stop them, but failed. To get the other Emeralds together, Eggman hosted the EX World Grand Prix, whose contestants had to paid an entrance free of one Chaos Emerald and where the winner could claim all seven. With Sonic, Sonic's friends, and the Babylon Rogues joining the competition, all seven Chaos Emeralds were eventually brought together. When Jet "won" the final race against Sonic, he claimed the seven Chaos Emeralds and used them to power the Key to Babylon Garden which raised Babylon Garden from Sand Ruins.

In gameplay, the yellow Chaos Emerald is used to depict the Chaos Emerald Extreme Gear. However, during races, this Extreme Gear takes the appearance of the Blue Star.

Sonic Riders: Zero Gravity
In Sonic Riders: Zero Gravity, the yellow Chaos Emerald is used to depict the Chaos Emerald Extreme Gear. However, during races, this Extreme Gear takes the appearance of the Blue Star.

Sonic Free Riders
In Sonic Free Riders, all seven Chaos Emeralds are used to depict the Chaos Emeralds Extreme Gear. However, during races, this Extreme Gear takes the appearance of the Blue Star.

Sonic the Hedgehog (2006)
In Sonic the Hedgehog (2006), Chaos Emeralds from different time periods were drawn into the insuring conflict.

When this incident began, the blue Chaos Emerald was in the possession of Princess Elise. The Chaos Emeralds were later targeted by Dr. Eggman who needed them to unlock the secrets of the Flames of Disaster, which were sealed inside Elise. As such, he tried to kidnap Elise and take her Chaos Emerald. However, Sonic got in the way. Elise later passed the blue Chaos Emerald on to Sonic when she got taken away by Eggman. In the meantime, after being freed from the Scepter of Darkness, Mephiles the Dark somehow acquired the purple Chaos Emerald.

The blue Chaos Emerald was eventually handed over to Eggman by Sonic in exchange for Elise's release. However, after Sonic relinquished the Emerald as instructed, Eggman broke his promise and sent Sonic, Tails and Knuckles to the future with a new machine. Eggman later used the blue Chaos Emerald to power his Egg-Genesis, but it was claimed by Silver and Blaze after they destroyed the robot.

In the future, Sonic and his friends met Shadow and Rouge. Seeking to get back to their own time, the group began seeking Chaos Emeralds to use to create a space-time rift back to their own time with Chaos Control. In the meantime, Mephiles, who had arrived in the future, showed Silver (who had yet to go back in time with Blaze at that point) a fabricated vision of Sonic surrounded by flames through his purple Chaos Emerald for his plot to manipulate Silver into killing Sonic. Eventually, Shadow and Rouge found the green Chaos Emerald whilst exploring Crisis City. Afterward, their group located the turquoise Chaos Emerald in Flame Core. Upon retrieving the Emerald however, they awoke Iblis, forcing the group to fight him off. Once Iblis was defeated, Sonic and Shadow used the green and turquoise Emerald to create a space-time rift, although Shadow remained behind to confront Mephiles.

After making it back to the present, Shadow fought Silver. During the fight Shadow used his green Chaos Emerald to use Chaos Control on Silver. In response, Silver used his blue Chaos Emerald to counter Chaos Control with Chaos Control. The result created a space-time rift which Shadow and Silver ended up using to go back in time to when Iblis and Mephiles got divided from Solaris during the Solaris Project. When Silver caught Iblis, the Duke of Soleanna used the white Chaos Emerald he had on him to chant and seal Iblis inside his seven-year-old daughter Elise, so long as she abstained from crying, with the only other stipulation being that the vessel must be of royalty. Afterward, Silver received the white Chaos Emerald from the Duke before he died. With Mephiles having been sealed as well, Silver gave the blue Chaos Emerald to an unconscious Elise to keep as a lucky charm (which showed how Elise came to possess it in the present). Using then the green and white Chaos Emerald, Shadow and Silver created a space-time rift to return to the present with.

The turquoise and white Chaos Emeralds were soon after used by Sonic and Silver to create another space-time rift. With it, Sonic planned to change Elise's fate after the Egg Carrier crashed with her inside it. Before going through the rift however, Sonic gave his turquoise Emerald to Silver. He and Blaze then went back to the future where Silver planned to use the two Chaos Emeralds he had to seal Iblis of his time inside himself. However, while the Emeralds were able to channel Iblis, the entity rejected Silver as a vessel. Blaze, who was a qualified vessel, therefore stepped in and used the Chaos Emeralds to seal Ibis inside herself and then use Chaos Control to sent herself and Iblis to another dimension. Meanwhile, back in the present, Mephiles went hunting for Chaos Emeralds, which he needed to rejoin with Iblis. After finding the yellow Chaos Emerald in Dusty Desert, Team Dark confronted him, prompting Mephiles to use the yellow Chaos Emerald against them. After being defeated however, Mephiles recovered and used both the yellow and green Chaos Emerald (which he apparently took from Shadow) in conjunction with his self-replication powers to mass-produce duplicates of himself, which Team Dark promptly engaged.

Deciding to kill Sonic himself and fill Elise with so much grief that she would cry, Mephiles used his purple Chaos Emerald to distract Sonic and Elise as they walked together while he impaled Sonic from behind. Following Iblis' subsequent release, Mephiles used his purple Chaos Emerald to warp all six of the other Emeralds to his location. Using the Emeralds' full power, Mephiles remerged with Iblis, thereby recreating Solaris. Later, Sonic's friends searched through the End of the World for each of the Chaos Emeralds after Solaris scattered them. Lastly, Elise, sharing the hopes and desires of the remaining cast to revive Sonic, used all seven Chaos Emeralds to bring Sonic back to life, in the form of Super Sonic, who then shared his power with Shadow and Silver, turning them into Super Shadow and Super Silver. Together, the trio of hedgehogs defeated Solaris and saved time itself from destruction.

In this game, the Chaos Emeralds are depicted as seven brilliant cut gemstones in the colors they have had since Sonic Adventure. However, these emeralds appear slightly smaller in size, and give off gleaming sparks of light of their respective colors.

In gameplay, the acquisition of the Chaos Emeralds were integrated into the mainstream story line, instead of being an objective the player had to accomplish in different levels. Also, in End of the World (which consists of pieces of different Action Stages), the Chaos Emeralds serve as the different sections' goals for the cast of playable characters. Tails finds the yellow Emerald in Crisis City; Omega finds the green Emerald in Flame Core; Knuckles finds the turquoise Emerald in Tropical Jungle; Silver finds the white Emerald in Dusty Desert; Rouge finds the purple Emerald in Wave Ocean; Amy finds the blue Emerald in White Acropolis; and Shadow finds the red Emerald in Kingdom Valley.

Sonic Rivals
In Sonic Rivals, each of the seven Chaos Emeralds makes an appearance as one the collectible cards in the game. These cards depict the Chaos Emeralds as they appeared in Sonic Heroes. To collect each card, the player has to fulfill the following conditions:


 * Green Chaos Emerald card: Complete all challenges for Forest Falls Zone.
 * Turquoise Chaos Emerald card: Complete all challenges for Colosseum Highway Zone
 * Red Chaos Emerald card: Complete all challenges for Sky Park Zone
 * Yellow Chaos Emerald card: Complete all challenges for Crystal Mountain Zone
 * Blue Chaos Emerald card: Complete all challenges for Death Yard Zone
 * Purple Chaos Emerald card: Complete all challenges for Meteor Base Zone
 * White Chaos Emerald card: Complete every challenge in the game

Sonic Rivals 2
In Sonic Rivals 2, the Chaos Emeralds were targeted by Dr. Eggman Nega, who needed them to set the Ifrit loose upon the world. This Ifrit resided in another dimension which could only be accessed through a portal in Mystic Haunt Zone, and the key to opening this portal were the seven Chaos Emeralds. To gather the Chaos Emeralds for him, Eggman Nega hired Rouge to search for them, albeit without revealing his identity or plans for the Emeralds. Rouge assumed, however, that her client would protect the Chaos Emeralds. Learning of Eggman Nega's plans, Dr. Eggman sent Metal Sonic (who was holding the green Chaos Emerald inside him) out to recruit Shadow and help him stop Eggman Nega.

During her hunt for the Chaos Emeralds, Rouge discovered a Chaos Emerald beneath a Chao. However, Espio, who had to distract Rouge and get the local Chao, took both the Chaos Emerald and the Chao away. Eventually though, the two fought over their respective targets. In the end, Rouge got the Chaos Emerald. Soon after, Rouge detected two Chaos Emeralds with her Emerald Detector.

By the time Rouge reached Mystic Haunt Zone as her client had instructed, Rouge was in possession of six of the Chaos Emeralds. Upon discovering her client's identity however, Rouge refused to hand the Chaos Emeralds over. By this time though, Metal Sonic had already arrived at the scene. With all seven Chaos Emeralds in one place, the portal to the Ifrit's dimension opened. Fortunately, the various individuals opposing Eggman Nega kept the Ifrit from leaving its dimension. During this, the six Chaos Emeralds Rouge had were seemingly lost. Metal Sonic later extracted the Chaos Emerald he held from inside his body when he and Shadow got trapped in the Ifrit's dimension after closing the portal. Receiving the Chaos Emerald from Metal Sonic, Shadow warped himself and Metal Sonic back to their dimension with Chaos Control.

Super Smash Bros. Brawl
In Super Smash Bros. Brawl, all seven Chaos Emeralds are shown when Sonic transforms into Super Sonic and when he turns back to normal. The Chaos Emeralds can also be seen on Super Sonic's trophy. Also, in one of Sonic's victory poses Sonic holds the blue Chaos Emerald.

Super Smash Bros. for Nintendo 3DS and Wii U
In Super Smash Bros. for Nintendo 3DS and Wii U, Sonic will show the seven Chaos Emeralds when he transforms into Super Sonic and when he reverts back to normal. In the Wii U version of the game, the Chaos Emeralds can also be seen as a part of Super Sonic's trophy. Also, as a part of one of his victory poses on both versions of the game, Sonic will grab and hold the blue Chaos Emerald.

Super Smash Bros. Ultimate
In Super Smash Bros. Ultimate, Sonic calls forth the seven Chaos Emeralds when he transforms into Super Sonic and when he reverts back to normal. Also, one of Sonic's victory poses shows hin grabbing the blue Chaos Emerald. In addition, Shadow, who appears as an Assist Trophy, uses the green Chaos Emerald to perform Chaos Control.

Sonic Chronicles: The Dark Brotherhood
In Sonic Chronicles: The Dark Brotherhood, the emeralds are stolen one-by-one by the lost clan of echidnas known as the Nocturnus Clan (who are often referred to as the "Marauders") in order to use their magnetic relationship with the Master Emerald to attract the Master Emerald and Angel Island itself to their base of operations. The Chaos Emeralds later are taken by Ix into the Twilight Cage, and distributed amongst the Kron (to power their factory), the Zoah (as a power source for a secret weapon to use against the N'rrgal), the N'rrgal (as a weapon against the Zoah), the Voxai Overmind, and Ix's two Gizoid prefects, Scylla and Charyb. At the end of the game, the emeralds are all brought back together and Sonic uses them to become Super Sonic and fought Ix in his Super State. This also includes the Great Emeralds, which are emeralds that have been charged up with Voxai power.

Sonic Unleashed
In Sonic Unleashed, after being caught by an early design of Eggman's "Egg Dragoon", Sonic summons the power of the Chaos Emeralds and becomes Super Sonic to destroy Eggman's fortress. However, Eggman traps Super Sonic in his Chaos Energy Cannon which removes the emeralds from him, reversing his super transformation and drains the emeralds of all of their power in order to power his laser, designed to awaken and release Dark Gaia from the planet. From there, the emeralds are left completely black and powerless, and are taken by Sonic and Light Gaia to the seven sacred shrines on different parts of the planet.

The Emeralds' powers are restored one-by-one, and the seven continents are put back into place as each emerald is restored. At the end of the game, while inside each of the shrines, Light Gaia asks the Chaos Emeralds to bring the shrines to him, and the emeralds, as well as the shrines, appear inside the core of the planet, with the shrines combining together to build the Gaia Colossus, which Light Gaia controls via his own power. The Chaos Emeralds are lastly used by Sonic to become Super Sonic again.

Mario & Sonic at the Olympic Winter Games
In Mario & Sonic at the Olympic Winter Games, the Chaos Emeralds appear in the Dream Figure Skating (Sonic) event. The player's team must recover the Emeralds from Flappers and then use them to defeat a frozen version of Perfect Chaos.

Mario & Sonic at the Rio 2016 Olympic Games
In Mario & Sonic at the Rio 2016 Olympic Games, the Chaos Emeralds appear as an item in the duel Rugby event. When the Emerald is activated, it creates an impact which will push opponents away. This breaks the trend of the Emerald's effect to paralyze all opponents for while.

In the Nintendo 3DS version of the game, the Chaos Emeralds raise special attack during the Boxing plus event.

Sonic Colors
In the Wii version of Sonic Colors, the Chaos Emeralds only appear in the Game Land. To collect the Chaos Emeralds the player must unlock and finish all the Sonic Simulator levels which requires gathering all 180 Red Star Rings in the game. Once done, the option to use Super Sonic must be activated from the options menu. Sonic cannot use Wisps in this mode (an alternate route appears in areas that absolutely need Wisps), and requires fifty rings to transform, but he gains bonus points every few seconds it is active and has infinite boost power, Super Sonic retains most of his old mannerisms in games like Sonic the Hedgehog 2 such as gliding when picking up speed (and the fact Sonic needs fifty rings to transform once more as usual). In the Nintendo DS version of Sonic Colors, Chaos Emeralds are once again collected through Special Stages. After all of them are obtained, Super Sonic is playable only to beat a secret, optional boss called Nega-Mother Wisp.

Sonic Generations
In the Xbox 360/PS3/PC versions of Sonic Generations, both Sonics must collect the Chaos Emeralds to battle Time Eater.

For unknown reason (possibly due to the Time Eater) the Emeralds ended up in the White Space. There, the purple Emerald is found by Classic Metal Sonic, the yellow Emerald is found by Shadow, and the white Emerald is found by Silver. The remaining Emeralds end up getting drained of their color and drift through the White Space, and the Sonics have to restore them by fixing the worlds. After Modern Sonic defeats the second boss, the Time Eater appears but is repelled by the now-colorless red Chaos Emerald. After the Sonics restore the last world, the red Chaos Emerald regains its color and Modern Sonic catches it by performing a Air Boost, much to the amazement of Classic Sonic.

To gain access to the Center of Time, the player to place all the Chaos Emeralds into the broken gears at the Lair of the Time Eater. During the final confrontation when both Sonics get badly injured by the Time Eater, Sonic's friends appear and cheer on both Sonics. The Chaos Emeralds then emerge from the Sonics, reacting to their friends' encouragement and they transform both of them into Super Sonic.

In the 3DS version, Modern Sonic gets the Chaos Emeralds through Special Stages, available after completing both acts of a zone. These are modeled after the Special Stages from Sonic Heroes, as Sonic must collect orbs and boost to the Emerald before the stage runs out.

Sonic the Hedgehog 4
Beginning with Episode I, collecting the emeralds works the same way as it did in the original Sonic the Hedgehog game, by collecting fifty rings and entering the Special Stage at the end of an Act. Sonic would then need to navigate through a series of mazes that constantly tilt clockwise and counterclockwise, with many obstacles to reach the emerald. In Episode II, the emeralds are obtained by reaching the end of an act (with the exception of Boss Acts and the first Acts of Sky Fortress Zone and the Death Egg mk.II Zone) with fifty rings and jumping into the giant ring past the sign post, and completing Special Stages designed in a half-pipe, which pays homage to Sonic the Hedgehog 2.

Sonic Lost World
In Sonic Lost World, the player can once again collect the seven Chaos Emeralds in gameplay, although they are not involved in the game's storyline.

The way of collecting them differs between the versions of the game. In the Wii U/PC version, the player automatically obtains a Chaos Emerald whenever they collect all the Red Star Rings found in one of the game's worlds. The collected Chaos Emerald can then be found on the world's map, though interacting with it will only show the Chaos Emeralds the player has collected. In the Nintendo 3DS version, the Chaos Emeralds can, like in many other games, be collected by completing each of the seven Special Stages. Collecting all seven Chaos Emeralds allows the player to transform Sonic into Super Sonic in normal gameplay.

Sonic Runners
In Sonic Runners, the Chaos Emeralds were collected by Dr. Eggman using Emerald Detectors. Hooked up to Eggman's energy collecting devices, the Emeralds had their chaos energy drained so they could power Eggman's latest brainwashing laser cannon. Though Team Sonic reclaimed the Chaos Emeralds, they were all powerless by the time they got to them. When Sonic held onto the Chaos Emeralds in his showdown with Eggman, he was hit by Eggman's brainwashing laser. However, the Chaos Emeralds saved him by reabsorbing their energy from the laser. Using the Chaos Emeralds to become Super Sonic, Sonic destroyed Eggman's cannon before the Emeralds scattered again.

Sonic Forces
In Sonic Forces, the Chaos Emeralds do not have a role in the game's plot. However, they do appear when Sonic (Classic and Modern) turns Super Sonic after collecting fifty Rings.

Artificial Emeralds
It is possible to create synthetic Chaos Emeralds with the same wavelength and properties as the originals, but with less power as demonstrated by Tails. In addition, these fake Emeralds can be used to sabotage devices that require Chaos Emeralds to power them. In addition, because it had the same wavelength and properties as the originals, fake Emeralds also allow the user to access Chaos Powers just as a genuine Chaos Emerald would, like Chaos Control.

Number
In the first game of the series, Sonic the Hedgehog, there were six Chaos Emeralds. This was also true for the Game Gear/Master System games Sonic the Hedgehog and Sonic the Hedgehog 2. The number was extended to seven Emeralds in Sonic the Hedgehog 2 for the Mega Drive, and that number has been consistent ever since, with a few exceptions such as most other 8-bit titles.

In the arcade game Sonic the Fighters, in order to travel to the Death Egg II, the player must collect all the Chaos Emeralds. Each character held an Emerald in the "story mode", and to get another one from a different character, they must be defeated in a fight. However, instead of the traditional seven Emeralds, there are eight. The widely accepted reason for this is because there are eight fighters, and so Sega added another Chaos Emerald. Some fans believe that this eighth Emerald is fake, but it is usually treated as a gameplay device rather than a significant plot element. There is also the possibility that the eighth Emerald is in fact the Master Emerald because it was obtained by Knuckles. Though the Master Emerald is green, and Knuckles' Emerald was red, there is the possibility that the Master Emerald can influence the color of the Emeralds (including itself) in addition to the amount of power they will release. This would explain why the Emeralds occasionally appear pink or orange. Incidentally, the color of the Master Emerald can be manipulated due to a glitch in Sonic & Knuckles. Note that early Japanese manuals identified the Master Emerald as an eighth, larger Chaos Emerald. However, the term usually applies to the seven smaller Emeralds.

In Sonic the Hedgehog 3, after accessing the Sound Test and entering a code, the player has access to a secret, and very difficult, 8th special stage. Upon completion, this stage yields the gray Emerald. In Sonic 3 & Knuckles, after accessing the Sound Test, two unused Special Stages could be accessed (one Chaos Emerald stage, with the same layout as the one in Sonic the Hedgehog 3, but with different colored panels, and one Super Emerald Stage). They unlocked a "golden" Emerald (instead of the gray one as in Sonic the Hedgehog 3). After that, the player goes on to the Angel Island Zone stage. This Emerald is considered a glitch.

In Sonic the Hedgehog Spinball, there appeared to be sixteen Emeralds, all of which were dark blue.

Colors
In the original Sonic the Hedgehog, the six Emeralds were Blue, Green, Yellow, Red, Pink, and Silver. A seventh, purple Emerald then appeared in Sonic the Hedgehog 2. In Sonic the Hedgehog 3, the pink Emerald was replaced with a Turquoise one, and the Yellow Emerald became Orange. In Sonic the Fighters, there were eight emeralds, one for each playable character: Sonic (blue), Tails (orange), Knuckles (red), Amy (pink), Bean (green), Bark (yellow), Fang (darker purple), and Espio (violet). The orange emerald was colored yellow again in Sonic Adventure, and the colors of the Emeralds have remained constant ever since, as red, blue, yellow, green, white, turquoise and purple. The white Emerald often appears gray, and Sonic R had both a yellow and an orange Emerald instead of a blue/turquoise one (the Chaos Emerald was blue in the racing course it was found in, but the screen after the race shows it as turquoise). Strangely in Sonic Jump, the turquoise Chaos Emerald was replaced by a black-colored one.

(Early releases of the Jazwares Super Pack with the Super States of the three hedgehogs (Sonic, Shadow, and Silver) and the seven Chaos Emeralds had the orange emerald instead of the turquoise emerald. The orange emerald was replaced with the light blue/turquoise emerald in newer packs.)

Certain games have used their own unique colors for the emeralds - in the 8-bit version of Sonic the Hedgehog they are light blue, dark blue in Sonic Spinball, while in Sonic Battle they are all green. In Sonic Chronicles: The Dark Brotherhood the Emeralds were red, light blue, turquoise, pink, yellow, orange and purple.

Sonic the Hedgehog Story Comic
Chaos Emerald is mentioned in Sonic the Hedgehog Story Comic Volume 1. According to Doctor Eggman, Chaos Emerald contains unfathomable energy and nobody has ever been able to find one before. With one of it, he'll be able to boil world's largest egg in the world's largest pot, which has been dreaming since as a child. One of Eggman's robots detects a Chaos Emerald from north west of South Island, in Green Hill Zone. Chaos Emerald is never mentioned in later volumes.

Sonic the Comic
In the UK's Sonic the Comic, the Chaos Emeralds were originally green Raw Emeralds from the Sacred Emerald Mine of the ancient Echidnas, but were infused with chaos energy by the Drakon Empire in the distant past. When brought together outside of certain stabilizing conditions (e.g. extreme cold), the Chaos Emeralds generate a chain reaction of chaos energy and warp to the Special Zone.

Six of the Chaos Emeralds were brought to Mobius in the distant past, and subsequently used by Doctor Ovi Kintobor in an attempt to rid Mobius of evil with his Retro-Orbital Chaos Compressor (ROCC). An accident involving the Emeralds and the ROCC transformed Kintobor into Doctor Ivo Robotnik.

The Emeralds were gathered by Sonic and protected from Robotnik, but were eventually returned to the Floating Island and placed in the care of Knuckles, the appointed Guardian of the Chaos Emeralds.

Archie Comics
In the Sonic the Hedgehog comic series and its spin-offs published by Archie Comics, the Chaos Emeralds were originally said to physical embodiments of the "Chaos Force", the all-encompassing force of the universe, and were much more numerous. A seemingly rare mineral, they could be found all across the universe, each coming in a different color depending on the celestial body. They are also connected to the "Power Rings", which are by-products of the emeralds. In addition, there exist rare 'Super Emeralds', created from unique Chao.

The central planet in the comics' storyline, Mobius, was given its supplies of green Chaos Emeralds during the mysterious event known as the Coming of the Chaos Emeralds. Their power were harnessed to revolutionize the world and gave as well rise to various villains and demi-gods, such as Mammoth Mogul and the Ancient Walkers. For ages, the Chaos Emeralds were a focus of much conflict on Mobius. All the Chaos Emeralds in the universe were eventually brought to Mobius by the villain A.D.A.M., but Super Shadow and Turbo Tails managed to sent them all into the Special Zone. There, the Zone's new ruler, Feist fused all of them into the seven differently colored jewels which he would hand out to those who could complete his challenges.

The seven emeralds were later used by Dr. Eggman and Dr. Wily to reshape reality with the Super Genesis Wave, and though Sonic and Mega Man stopped them, Sonic's multiverse was left heavily altered. In this new reality, the Chaos Emeralds and their background are the exact same as those in the games.

IDW Publishing
The Chaos Emeralds are mentioned in the Sonic the Hedgehog comic series and its spin-offs published by IDW Publishing.

Adventures of Sonic the Hedgehog
In the Adventures of Sonic the Hedgehog television series, the Chaos Emeralds are five (initially four) green emeralds in different shapes. They are hidden in different time periods, and each emerald focuses on a different power:
 * Invisibility: Makes the holder invisible.
 * Invincibility: Grants the holder invincibility and superhuman strength.
 * Immortality: Grants the holder immortality and invulnerability.
 * The power of life: Enables the holder to take away life or bestow it.
 * Chaos Emerald Ring: The most powerful of the Chaos Emeralds.

In a quest for the first four Chaos Emeralds, Dr. Robotnik rampaged through time to find them, but was stopped at every turn by Sonic and Tails. Regardless, Robotnik still managed to get the emeralds and used their power to become the Supreme High Robotnik, but Sonic, Tails and multiple incarnations of them from across time stopped him and returned the emeralds to their rightful places. Robotnik later discovered a fifth Chaos Emerald, but lost it to Sonic before he could use it.

Sonic Underground
In the Sonic Underground television series, the Chaos Emeralds made an appearance, but very little is known about them. Like in the games, they are a source of incredible power. Described as a green rare emerald variety, only two of them are known to exist.

Knuckles guards one Emerald on the Floating Island. Robotnik tried to steal this one and frame the Sonic Underground for the theft, but his plan failed. Robotnik later acquired another one for his Fortress of Altitude. Due to Sleet and Dingo's treachery however, the Chaos Emerald was broken, forcing the heroes and villains to work together to contain the unstable Emerald fragments before they could destroy Mobius.

Sonic X
In Sonic X, the Chaos Emeralds echoed their role in the games as objects that were sought after by all parties. In this media, the Chaos Emerald is described as a legendary stone that gives one the power to rule the world. Also, all seven being in one place results in them releasing energy that push them away from each other. This is likely this media's way of creating an explanation as to why the Chaos Emeralds end up scattering, as opposed to when in the video games they just seem to scatter for no reason.

Originating from Sonic's world, the Chaos Emeralds came to Earth during a massive Chaos Control amidst a battle between Sonic and Dr. Eggman. There, they were sought by Sonic and his friends to return home while Eggman sought them for various plots to conquer the planet. Eventually though, the Chaos Emeralds returned to the world from whence they when Sonic used them to go home. Six months later, the Chaos Emeralds were targeted by the Metarex, an alien race of cyborgs bent on universal domination, but Sonic and his allies managed to secure them and use them to stop the Metarex.

Emerald Shards
Emerald Shards are fragments of Chaos Emeralds crushed by Doctor Eggman found in Sonic Battle. They are used to operate the E-121 Phi model robots. Once an E-121 Phi is destroyed they drop their Emerald Shard and either break down or retreat. When five Emerald Shards of the same color are united, a Chaos Emerald can be created. Tails is the one who first discovered how Emerald Shards work and characters often visit him to have their Chaos Emerald reassembled which Emerl would soon absorb. Chaos Gamma is also seen with an Emerald Shard which he absorbs to injure Shadow.

Trivia

 * Emerald is the name of a specific gem of the beryl variety, a family known for its wide array of possibly colors. "Emerald" is also used in Japan as a generic term for jewels.
 * The current colors of the Chaos Emeralds are based on the three primary colors of light (red, blue, and green), the three secondary colors which are mixtures of the primary colors (red + blue = purple, blue + green = cyan, and green+ red = yellow), and finally gray which is a mixture of all three primary colors (red + blue + green = gray).
 * In Sonic the Hedgehog 2, if the player gets a Game Over (or finishes the game) and starts a new game via the Options menu, the number of Chaos Emeralds he/she had in the previous game is transferred over to the new game.
 * When the colors of the Chaos Emeralds are inverted, they simply swap colors, giving the appearance that the position of the Emeralds simply changed.
 * In most games, when causing a super transformation, the Emeralds surround the users in a circle and starts rotating around the users, before being absorbed.
 * In an unused Sonic Colors beta voice clip, Dr. Eggman stated that Chaos Emeralds are less powerful than Hyper-go-on.
 * However, since this line is ultimately unused, it cannot be officially guaranteed.
 * In Sonic the Hedgehog 2, it is possible to collect all seven within Emerald Hill Zone, provided the player is careful with the order in which Star Posts are activated (and very skilled at the Special Stages).
 * The gemstone-appropriate names for colored beryls are red beryl (red), golden beryl or heliodor (yellow), purple beryl (purple), emerald (green), aquamarine (turquoise/light blue), maxixe (deep blue), morganite (peach/pink), and goshenite (white). Some call red beryl bixbite, but this name is discredited.
 * The Chaos Emeralds that appear in the Tikal visions in Sonic Adventure are much larger than the Chaos Emeralds that appear elsewhere in the game.