Chaos Emerald


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

The Chaos Emeralds (カオスエメラルド) are reoccurring objects that appear in the Sonic the Hedgehog series. They are seven ancient emeralds and mystical relics tied to the Master Emerald, with 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 command ultimate power.

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 immeasurable 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.

Background
The Chaos Emeralds' background are 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 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 (which shifts along the sea due to the Emeralds' presence). 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 as 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 which was protected by a sacred barrier, where a colony of Chao lived peacefully. Among the shrine's inhabitants, the mystical water beast Chaos, the guardian spirit of the Chao, would assume the role of safeguarding the Chaos Emeralds. 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. 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, 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 were named the "Chaos Emeralds" by the surviving members of the Knuckles Clan due to their connection with Chaos, and they have since been primarily guarded by the echidnas.

Over fifty years prior to Shadow the Hedgehog, the Chaos Emeralds were researched by Gerald Robotnik for Project Shadow, which enable him to create the Chaos Drives, and for his studies of the Gizoid.

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 an everlasting source of energy. Oppositely, the Emeralds can absorb chaos energy exposed to them. By focusing one's thoughts, the Emeralds can even bend reality to achieve certain feats, such as showing visions, performing rituals, reviving the recently deceased and even make them react and 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 occasionally enhance the wielder's abilities. Harnessing all seven Chaos Emeralds will bestow 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 bestow them with a Super State. However, Super States generally do not last long, as they consume tremendous amounts of energy. The Emeralds can also be harnessed to power machinery, such as the Eclipse Cannon. Potentially, their power can as well 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 it, 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 appear to 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 appear to possess some form of sentience, as they can seemingly act on their own and remain stable despite the current conditions. Supposedly, this also explains for their tendency to show up where they are most needed.

Each Chaos Emerald is linked to each other and act like magnets that can attract or repel 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. After using all seven Emeralds though, 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.

Sonic the Hedgehog (1991)
In the original Sonic the Hedgehog for the Sega Genesis, there are six Chaos Emeralds which can be found in each of the six Special Stages. In the game, while Dr. Robotnik has been taking over South Island, he has been searching for the Chaos Emeralds which are lying somewhere on the island.

After getting the six Chaos Emeralds and clearing the game, the player gets the good ending of the game; after foiling doctor's plans, Sonic returns to the Green Hill Zone, where the Chaos Emeralds start to hover and rotate in the mid-air. After that, the Emeralds disappear in a flash, with new kinds of flowers having appeared around the Green Hill Zone for Sonic. In the bad ending, 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.

While the plot is mostly identical in the 8-bit version of Sonic the Hedgehog, the Chaos Emeralds are not found in the Special Stages, but rather, each one of them are hidden in the game's regular Zones. Each of six Chaos Emeralds are worth of 20,000 points at the Zone's game's score and are colored dark blue in the game. Collecting all six Chaos Emeralds changes the ending, where they start hovering above South Island from Sonic's hands and dispose of the pollutant above the island caused by the Scrap Brain Zone. After that, the Chaos Emeralds vanish.

While in the Sega Genesis each Emerald bear a different collor, in the Master System version of Sonic the Hedgehog (8-bit) the six Emeralds share the same color: light blue.

Sonic the Hedgehog 2
In Sonic the Hedgehog 2, all seven Chaos Emeralds are featured for the first time, which can be collected by completing each of the seven Special Stages in the game. In the game, Dr. Robotnik is once again after Chaos Emeralds, which are this time lying somewhere on West Side Island to finish his newest creation, the Death Egg. When the player obtains all seven Chaos Emeralds, Sonic is able to turn into Super Sonic in regular Zones, and, if the game is locked on to Sonic & Knuckles, Knuckles can turn into Super Knuckles. Collecting all of them will unlock the good ending of the game as well; instead of being saved by Tails as in the bad ending, Super Sonic flies from exploding Death Egg in the last second, with Tails on the Tornado and a Locky herd flying behind him in the sky.

In the 8-bit version of the game, Dr. Robotnik kidnapped Tails and demands Sonic to bring six Chaos Emeralds as ransom request. Five of the Chaos Emeralds are hidden inside each of the game's Zones while Silver Sonic in Scrambled Egg Zone is holding the sixth Chaos Emerald. After collecting the five Chaos Emeralds and defeating Silver Sonic, Sonic is granted access to the Crystal Egg Zone, where he defeats Robotnik and rescues Tails.

Sonic the Hedgehog 3 & Knuckles
In Sonic the Hedgehog 3, which takes place after Sonic the Hedgehog 2, Sonic is possessing all seven Chaos Emeralds when he and Tails arrive to investigate Angel Island. As they approach Angel Island, Sonic uses the Emeralds to enter his Super State and storms the island, but on the island Knuckles the Echidna ambushes him and makes him lose all seven Chaos Emeralds, which Knuckles then steals and hides away on the island. In the game, the Chaos Emeralds can be once again collected after each of the game's Special Stages. Like in previous installment, the player can turn into Super Sonic and the ending is slightly different.

In Sonic & Knuckles, Chaos Emeralds can be obtained from different Special Stages and both Sonic and Knuckles can turn into their own Super States by collecting all seven each. With Chaos Emeralds, the player can also enter the Doomsday Zone to clear the game with different ending. However, in the lock-on Sonic the Hedgehog 3 & Knuckles, when the player arrives at Mushroom Hill Zone and touches the rainbow-colored Giant Ring at the beginning of the Zone, he/she gets transported to the Hidden Palace Zone, where Chaos Emeralds become Super Emeralds which the player can collect. After this sequence, the player is unable to turn into Super State again, but there is change to skip the rainbow-colored Giant Ring, enter the Doomsday Zone and finish the game with just Chaos Emeralds.

Sonic Adventure
In Sonic Adventure, the Chaos Emeralds were collected by Eggman in order to feed Chaos, the guardian of the Chao and Emeralds, and it changed form every time it received one of the gems. With all seven, it became Perfect Chaos, and used up all of the negative energy in the Emeralds before dropping the dull-colored emeralds (which are left with positive energy) onto the ground. Sonic then picked all seven up and used the positive energy to become Super Sonic and destroy Perfect Chaos. Also in the game, Tikal states that "The 7 Emeralds can change our thoughts into power", and that the Master Emerald controls that power.

This is the first game in which the acquisition of the Chaos Emeralds are integrated the mainstream story line, instead of requiring to enter Special Stages.

Sonic Adventure 2
In Sonic Adventure 2, Sonic and Shadow had the ability to use the Chaos Emeralds to utilize "Chaos Control", an ability that alters time and space to teleport or freeze time. Interestingly, Sonic, at one point, uses the Chaos Control ability with a fake Emerald that had the same wavelengths and properties as a real one. Shadow told Eggman to collect a few Chaos Emeralds in order to get enough power for the Eclipse Cannon. In the end side Eggman had six Chaos Emeralds and he was able to destroy half the moon.

Tails soon managed to produce a "fake Chaos Emerald" that Sonic used in order to teleport back to the Space Colony ARK when Eggman sent him to space in an explosive capsule. Eggman stole the real emerald from Tails and put into to the Eclipse Cannon; however, when all seven were collected, the ARK started to fall toward Earth in order to kill millions of innocents for vengeance of Gerald Robotnik. The Chaos Emeralds were disabled by Knuckles, who used the Master Emerald, but when it appeared to be useless, as Biolizard was controlling the ARK, Sonic and Shadow used the emeralds to transform into their Super States for the last battle.

Sonic Advance
In Sonic Advance, the Chaos Emeralds are attainable from Special Stages. When all seven are collected, the player can access The Moon Zone during Sonic's gameplay or start his game from the said zone, allowing the player to see the true ending of the game. The Chaos Emeralds are shared among the cast of the playable characters so any character can collect any of the Chaos Emeralds for Sonic to access The Moon Zone.

Sonic Advance 2
In Sonic Advance 2 the Chaos Emeralds are once again attainable from Special Stages. Unlike Sonic Advance, the Chaos 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. If all four characters each have collected the seven Chaos Emeralds, Amy becomes an playable character.

Sonic Advance 3
Much like its previous installments in the series, the Chaos Emeralds in Sonic Advance 3 are attained from Special Stages. After all seven Chaos Emeralds are collected, the player can access Nonaggression after defeating the final boss with Sonic as the team leader.

Sonic Heroes
In Sonic Heroes, the gameplay pays homage to classic elements, so it goes back to a way of collecting the Chaos Emeralds from Special Stages to unlock the Last Story. Just before the battle against Metal Overlord, Sonic became Super Sonic and he gave some of his energy to Tails and Knuckles, turning them into Super Tails and Super Knuckles. Each Chaos Emerald is collected in the following color order: green, blue, yellow, gray, turquoise, purple, and red.

Shadow the Hedgehog
In Shadow the Hedgehog, the Emeralds were found throughout the stages (again, Special Stages weren't used), and Shadow collected all seven by the end of the game, only to let them be stolen by the evil alien Black Doom, who used a superpowered Chaos Control to bring the Black Comet to Earth's surface. Shadow then got the Chaos Emeralds back and transformed into Super Shadow in order to destroy Black Doom and teleport the Black Comet into space to be destroyed by the Space Colony ARK's Eclipse Cannon, the cannon itself using the Chaos Emeralds as its power source.

Sonic Rush
In Sonic Rush the Chaos Emeralds are necessary to access the final stage of the game. Special Stages make a return as a way to obtain the Emeralds. The Emeralds are shown to have an inter-dimensional counterpart, the Sol Emeralds, with similar powers. The Chaos and Sol Emeralds' powers are shown to come from the positive emotions of their wielders in this game and they are used by both Sonic and Blaze to transform into their Super States.

Sonic Jump
In Sonic Jump, the Chaos Emeralds can be obtained by completing an act with at least fitfy Rings to obtain a fragment of it. In the game's plot, Eggman schemes to use the power of the Chaos Emeralds to power his Brainwash Beam but Sonic stops him, causing the Emeralds to scatter themselves. Sonic then eventually retrieved all of them (after getting the last one from Eggman).

Sonic the Hedgehog (2006)
In Sonic the Hedgehog (2006), the Emeralds fully take on the power to "transform thoughts into power", just as the Master Emerald was said to be capable of doing in Sonic Adventure. These emeralds appear slightly smaller in size, and give off gleaming sparks of light of their respective colors, and are given the additional title of "miracle gems".

In this game, the Duke of Soleanna proved that humans can access the power of the Chaos Emeralds by using a single emerald to chant and seal the newly born Iblis into his daughter's soul, so long as she abstain from crying, with the only other stipulation being that the vessel must be of royalty. Mephiles succeeds in mass-producing duplicates of himself using two Emeralds, and showing Silver a fabricated vision of a smug-looking Sonic surrounded in flames, through the Emerald itself.

Only six of the Chaos Emeralds appeared in this game: the green emerald (which Shadow and Rouge found whilst exploring Crisis City in the future. They then used it along with the dark blue emerald to go back to the present while Shadow stayed in the future to battle Mephiles. Rouge then gave the Chaos Emerald to E123-Omega to give to Shadow in the future so as to escape Mephiles. Mephiles later used its power along with the yellow emerald to battle Shadow), the blue emerald (which was owned by Elise who then gave it to Sonic when she was captured. Sonic then gave it to Eggman so as to ensure Elise's release. Eggman then put the emerald into his Egg Genesis which Silver and Blaze defeated and obtained the emerald themselves. Silver then gave it to younger Elise in the past as a good luck charm, which showed how Elise came to possess it in the present), the yellow emerald (which Mephiles went after at the end of Shadow's storyline and used to battle Shadow in conjunction with the green emerald), the white emerald (which the Duke of Soleanna sealed Iblis inside Elise's body with. The duke then gave the Emerald to Silver right before he died which Silver used to go back to the future so as to seal Iblis. Blaze then used it and the turquoise Emerald to seal Iblis away into a different dimension), the turquoise emerald (which Sonic and Shadow obtained from defeating Iblis so as to go back to the future. Sonic then gave the Emerald to Silver, which Blaze used in the future along with the white emerald to seal Iblis away) and the purple emerald (which Mephiles was shown to have the entire way through the series). The red emerald meanwhile was never seen in the main story lines until the Last Story, although it is possible that it is the one Dr. Eggman located when he searched for the Chaos Emeralds on his ship.

Mephiles also somehow uses some sort of ability when he uses the purple Emerald in his possession to warp all six of the other Emeralds to his location, possibly using the magnetic properties of the Emeralds, and uses their full power to begin his and Iblis' transformation into Solaris. Sonic's friends then have to search through the world's end for each of the Chaos Emeralds: Tails: Yellow, Omega: Green, Knuckles: turquoise, Silver: White, Rouge: Purple, Amy: Blue, Shadow: Red. Lastly, Elise, sharing the hopes and desires of the remaining cast (possibly even including Eggman) to bring Sonic back to the land of the living, uses all seven Chaos Emeralds to bring Sonic back to life, in the form of Super Sonic, who thanks Elise and shares his power with fellow hedgehogs Shadow and Silver.

Sonic Riders
In Sonic Riders, the first one to be seen was stolen by the Babylon Rogues but it is unknown which one it was. After that, the only time they are featured was as the entry fee for the World Grand Prix. When Jet "won" the final race against Sonic, he claimed the seven Chaos Emeralds as his prize and used them to power the Key to Babylon Garden as Dr. Eggman had instructed to raise Babylon Garden from Sand Ruins.

Sonic Rush Adventure
In Sonic Rush Adventure it is suggested by Blaze that the Chaos Emeralds have a mind of their own. They appear in her dimension for no indicated reason and one must race Johnny for the Chaos Emeralds, although it is possible that Sonic had them with him before he arrived in the Sol Dimension and they scattered during the transition.

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.

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. In one of Sonic victory poses Sonic holds the blue Chaos Emerald.

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 players 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 & 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 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. Classic Sonic gets the purple and green Emeralds and Modern Sonic gets the yellow, blue, white, red and turquoise Emeralds.

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 though 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 perform 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' encouragements 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, though it will have no impact on the storyline of the game.

The way of collecting them differs between the versions of the game. In the Wii U/PC, 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.

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 Sonic Adventure 2. In addition, the artificial Emeralds can be used to sabotage devices that require Chaos Emeralds to power them. It was because of this that Tails attempted to place a fake Chaos Emerald into the Eclipse Cannon console and render it inoperable. In addition, because it had the same wavelength and properties as the originals, artificial emeralds also allowed the user to access Chaos Powers just as a genuine Chaos Emerald would, which is especially apparent with how Sonic escaped from a pod rigged to explode.

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 (in Sonic Advance/Sonic Rush order) 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, but 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.

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: Mades 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.
 * "Chaos" in the English language means disorder and an irregular, unpredictable action that was remarkably sensitive to regular changes in environment, similar to how the Chaos Emeralds in the series act. "Chaos" as used in Greek refers to a large emptiness, or space. "Space" in English came to be a general term meaning both everything outside of the Earth’s atmosphere and the placement of objects in relation to one another.
 * 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 grey which is a mixture of all three primary colors (red + blue + green = grey).
 * 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.
 * The Chaos Emeralds are not indestructible as shown in Sonic Battle; the Emeralds have been seen breaking but are easily repaired.
 * 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 surrounds the users in a circle and starts rotating around the users, before being absorbed.
 * In Sonic Colors (Wii), Sonic Generations (Console and PC with the Super Sonic skill equipped), and Sonic Lost World, Sonic transforms before the Chaos Emeralds enter his body.
 * In an unused Sonic Colors voice clip, Dr. Eggman stated that Hyper-go-on is more powerful than Chaos energy.
 * However since this line is ultimately unused, it cannot be officially guaranteed.
 * In Sonic 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 scarlet emerald (red), golden beryl (yellow), emerald (green), aquamarine (turquoise), blue goshenite (blue), morganite (purple), and goshenite (white).
 * Starting with Sonic R, the Chaos Emeralds themselves took on a brilliant diamond cut which has been game canon ever since.
 * It should be noted that in Shadow the Hedgehog, the Chaos Emeralds are brighter, while in gameplay, they are dark and resemble more how they looked in previous games, but bigger.
 * 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.