Power Gem

Power Gems are collectables in The Legend of Zelda: Phantom Hourglass. There are 20 in total and are found all over the Great Sea. Once you obtain ten, the Spirit of Power gains power and a new ability can be used. Gaining all 20 increases the Spirit's power further.

For the spirit of Power, getting 10 gems lets Link's sword light on fire and double attack power. Getting 20 quadruples the power.