The Chaos Emerald (ワープゲート Wāpugēto?, lit. "Warp Gate"), also known as the Special Monitor, is an item box power-up that appears in the Sonic the Hedgehog series. If opened under the right conditions, it can take the player to one of the game's Special Stages.
The Chaos Emeralds can be found inside the first five Zones of Sonic the Hedgehog Triple Trouble, with one hidden in the first two Acts of each Zone.
If the player breaks a Chaos Emerald while carrying fifty Rings or more, it will open a Star Circle above itself that leads into one of the Special Stage where a Chaos Emerald gem can be earned. After a Chaos Emerald has been used, a Super Ring monitor appears in its place after the player exits the Special Stage. However, if the player does not have fifty Rings when opening a Chaos Emerald monitor, nothing will happen.
- Sonic the Hedgehog Triple Trouble (Sega Game Gear) United States instruction booklet, pg. 8.
- Sonic & Tails 2 (Sega Game Gear) Japanese instruction booklet, pg. 19.
- Flynn, Ian; Sega (8 December 2021). Sonic the Hedgehog Encyclo-speed-ia. Dark Horse Books. p. 62. ISBN 978-1506719276. "Special stage - Collect fifty Rings, find the Special Monitor, and bust it open to unlock a shot as the Chaos Emerald. You'll need to either navigate a maze and battle Fang before time runs out or collect eighty Rings with the Tornado within a strict time limit."