White Gem

The White Gem is is an optional upgrade for Sonic the Hedgehog in Sonic the Hedgehog (2006) and is one of the seven customized Gems that can be obtained in the game. It allows Sonic to perform the Homing Smash, which allows Sonic to manipulate his Homing Attack. When in use, the White Gem changes the appearance and colors of Sonic's Power Sneakers into a gray pair of new shoes.

Location
In Sonic the Hedgehog (2006) the White Gem becomes available at the local shop, once the player clears Sonic's version of Kingdom Valley in the main story. It can then be bought for 8000 Rings.