Chaos Emeralds

First Game:Sonic the Hedgehog 1 (Genisis)

The 7 Chaos Emeralds (6 in Sonic 1) all powerful gems. When Sonic collects all 7 he is able to transform into the yellow/golden Super Sonic with invulnerability, extra speed, and increased jumping ability. Knuckles and Shadow can do a similar feat. Knuckels becomes Super Knuckles and flashing between his normal coloration and pink. Shadow becomes Super Shadow and turns silver.

No one knows where the Chaos Emeralds come from. They are from the anchient past. The power of the Chaos Emeralds can only be turned off by the Master Emerald.

There is an upgraded version of the Chaos Emeralds known as the Super Emeralds. These gems are far more powerful. With all 7 Super Emeralds Sonic becomes Hyper Sonic. Hyper Sonic flashes many colors with white between each color and leaves an image trail behind him. Hyper Sonic is able to do a mid-air dash that destroys any nearby enemies on execution. Knuckles is able to become Hyper Knuckles. Like Hyper Sonic, Hyper Knuckles leaves an image trail behind himself. When he glides into any wall he creates an enemy destroying earthquake. Tails becomes Super Tails with the Super Emeralds' power. He is enhanced just like Super Sonic but he has super Flickies come and help him take on any enemy in the area.

The Chaos Emeralds were never part of the plot until Sonic Adventure.