Force Gem

Force Gems are recurring items in the Legend of Zelda series. These small triangle-shaped gems have different purposes depending on what game is being played.

Origins and Nature
According to the Ocean King, Force Gems are physical manifestations of the life force present in every living thing, and the Sand of Hours is made from ground-up Force Gems of the Ocean King himself. According to Carben, this life force can crystallise into the form of Force Gems when a person feels strong gratitude. Force Gems also appear from the environment in Four Swords Adventures, suggesting that they can even come from nature. Force Gems are a source of mystical energy and can be used to power the Four Sword, the Phantom Hourglass and are used to power the seal on the Tower of Spirits by maintaining the Spirit Tracks. Force Gems also bear a strong resemblance to the Triforce, but the connection between the two (if any) is unknown.

The Legend of Zelda: Four Swords Adventures
Force Gems are the equivalent of Rupees in Four Swords Adventures. As Link collects them, they restore the Four Sword's power to repel evil. When Link acquires 2,000, the Four Sword is powered to the Ultimate Four Sword and is capable of doing the a longer version of the Spin Attack called the Hurricane Spin Attack and firing a Sword Beam. Though this is usually done cooperatively, many players fight one another for Force Gems, due to the ranking session at the end of each stage. The ranking session tallies up each player's total kills, deaths, and Force Gems and ranks players accordingly.

In Kakariko Village, a Fortune Teller will also take Force Gems as currency for a prediction, indicating how closely related to Rupees the gems are.

The Legend of Zelda: Phantom Hourglass
In the Temple of the Ocean King, there are two rooms where Link must find three Force Gems hidden around the rooms and place them in indentations upon a pedestal, creating the shape of the Triforce. Force Gems also appear in multiplayer mode; in this mode, Link must return as many Force Gems as possible to his base while the other player controls three Phantom Guardians trying to stop him. The largest gems yield 15 points, the medium sized gems yield 5 points, and the smallest gems yield 1 point. The roles switch when either time runs out or Link is caught.

The Legend of Zelda: Spirit Tracks
When Link defeats a boss, a huge Force Gem appears, in various colors, on a large mantle. Each one is different for each region of New Hyrule. It will restore some of the Spirit Tracks in that section.

Smaller Force Gems are also given to Link by the various inhabitants of New Hyrule when he has completed a certain task for them, causing them to feel gratitude. These Gems cause new sections of the Spirit Tracks to appear, which normally provide an easier path between locations or grant access to a new location. There are twenty-one of these total, most of which are optional, but some are required to progress in the game.

They also apear on the hilt of the Lokomo Sword.

Force Gems also appear on the top of Locomotive Musings.

In the 4-Player Battle Mode, Force Gems appear (with their original yellow design) as items that the four different Links can collect in order to win the game.

Trivia

 * Force Gems are identical to the Triforce pieces in the The Legend of Zelda animated series.