Magical Metals

Magical Metals (also called Blessed Metals) are metals that can be used by Greek and Roman Demigods and immortals to fight against monsters and other evil creatures, as well as gods and other demigods. The Greek gods and demigods use Celestial Bronze, while the Roman gods and their children use Imperial Gold. Hades, as well as those who live in the Underworld and his children (like Nico) use Stygian Iron.

Celestial Bronze
Celestial bronze is mined from Mount Olympus, then forged by the Cyclopes tempered in the heart of Mount Etna and cooled in the River Lethe. The metal does not harm mortals, considering them not important enough to injure, and is strong enough to cut through a steel door. It is also been mentioned that this metal glows when in weapon form.

Notable Celestial Bronze weapons

 * Riptide
 * Annabeth's Knife
 * Maimer
 * Backbiter (half Celestial Bronze)
 * Aegis
 * Thalia's spear
 * Katoptris

Imperial Gold
It is unknown where Imperial gold is mined from, but it is be consecrated it in the Temple of Jupiter on Capitoline Hill in Rome, as stated by Midas in The Lost Hero. The metal is extremely rare, but very powerful. It is also quite volatile. It is also thought that because of the blessing of Jupiter these weapons are more effective against Venti. This metal is favored by Roman Demigods. Whether the Roman aspect of the Gods carry weapons made of Imperial Gold or Celestial Bronze is unknown.

Notable Imperial Gold Weapons

 * Ivlivs
 * Frank's Spear
 * Hazel's Spatha
 * Juno's Gladius
 * Reyna's dagger
 * Chrysaor's weapons

Stygian Iron
A metal rarer than both Celestial Bronze or Imperial Gold. It's forged in the Underworld and cooled in the River Styx. It is possible that only people or beings of the Underworld can wield this metal (Hades, his children, and other beings that live in the Underworld). Where weapons made from the other Blessed Metals cause Monsters to disintegrate, Stygian Iron absorbs their essence causing them to cease to exist and thus not being able to reform ever again.

Notable Stygian Iron weapons

 * The Sword of Hades
 * Nico's sword
 * Thanatos' Sword
 * Hades' Staff