Pure Metal

The Pure Metals are three Quest Items that appear in Phantom Hourglass.

Quest Purpose
Link is told to find the three Pure Metals: Crimsonine, Azurine and Aquanine, so Zauz can forge the Phantom Sword, the only weapon capable of defeating the game's antagonist, Bellum.

List of Pure Metals
The first metal, Crimsonine, is found in the Goron Temple with the help of Gongoron, after defeating Dongorongo. The second is Azurine, found in the Temple of Ice after defeating Gleeok and breaking the curse on the Yook. The final Pure Metal, Aquanine, is found in Mutoh's Temple. It was a sacred treasure kept in King Mutoh's Tomb. After defeating a monster disturbing his sleep, Link earned the pure metal. All three Pure Metals are symbols of the empathy and trust placed in Link as he proves himself worthy of obtaining such rewards in the face of the Goron, Anouki, and Cobble tribes.

Trivia

 * In the Goron Village shop in Majora's Mask, there is a non-purchasable item that resembles Aquanine.
 * Phantom Hourglass is no stranger to the three-object tradition carried on by previous Zelda games, and shares this similarity in respect to the Pure Metals with the Pendants of Virtue, Spiritual Stones, and Goddess Pearls of earlier titles.
 * The Pure Metals share the same symbol adorned on the face of the Temple of the Ocean King. Considering the metals are used to forge the Phantom Sword, the weapon used to defeat Bellum, who resides at the base of said temple, the symbols provide a solid connection between the sword and the temple.
 * Crimsonine is very similar in appearance to the red diamonds found in Wario World.