Spirit Gem

Spirit Gems are an item found in The Legend of Zelda: Phantom Hourglass. The can be bought from Beedle or other various shop owners on different islands, found in chests, or given to you by various NPC's. There are three kinds of gems, Power, Courage, and Wisdom.

The Power Gem bears the symbol of Leaf, and symbolizes the Triforce of Power. When Link gains enough Power Gems and he takes them to Spirit Island, he receives a sword (attack strength) power-up (via Leaf).

The Wisdom Gem bears the symbol of Neri, and symbolizes the Triforce of Wisdom. When Link gains enough Wisdom Gems, and he takes the to Spirit Island, he receives a life (hearts/shield) power-up (via Neri).

The Courage Gem bears the symbol of Ciela, and symbolizes the Triforce of Courage. When Link gains enough Courage Gems, and he takes the to Spirit Island, he receives a sword (beam sword) power-up (via Ciela).