Also known as: カオスエメラルド
A group of seven gemstones from the Sonic the Hedgehog franchise. As they can serve as a source of tremendous power, they are usually sought after by the villains for use in their evil schemes.
When all seven are collected, they allow certain characters to transform into a more powerful form known as a "Super State". For example, Sonic The Hedgehog becoming Super Sonic.
While their exact colors may vary between different media, the most common setup is one emerald each in the colors blue, yellow, red, green, purple, turquoise/aqua, and white/gray.