Pure Metal

In Phantom Hourglass, Link is told to find the three Pure Metals: Crimsonine, Azurine and Aquanine, so Zauz can forge the Phantom Sword. The first metal, Crimsonine, was 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, was 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.

Trivia

 * In the Goron Village Shop in Majora's Mask, there is a non-purchasable item that resembles Aquanine.