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.
A Chaos Emerald in a Special Zone in Sonic the Hedgehog.
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.
Thank you for coming to /qa/ Questions & Answers