The Power Rock, also referred to as the Power Stone, is an object that appears in the Sonic the Hedgehog television series. It is a powerful stone located at the bottom of the Lake of Rings, which is a key component in the lake's production of Power Rings.
The Power Rock is a green-glowing stone of unknown origin. It typically sits in a small capsule-like machine located at the bottom of the Lake of Rings, and it is the power source that allows the machine in the Lake of Rings to produce Power Rings. With the Power Rock's power, this machine could produce a Power Ring every 24th hours. However, the process of creating Power Rings was later shorten to every 12th hour. The Power Rock can also be used as a power source for other machines. It also appears to be brittle, as Sonic could easily break a fragment off it.
Desperate to get a new power source for Lower Mobius, Griff stole the Power Rock from the bottom of the Lake Rings and took it with him to Lower Mobius. There, he placed the stone inside the generator for the crystal that provided light and heat to the entire Lower Mobius. Sonic, Sally and Antoine, having discovered the theft, soon after found a Power Rock shard at where Griff's Hover Sled was. Sonic later managed to recover the Power Rock from Griff, but decided to share it with him and thus broke off a fragment of the Power Rock. Sonic subsequently took his part back with him to Knothole Village and gave the fragment to Griff so that the light generator in Lower Mobius could run for a while longer.