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, those who live in the Underworld, and some of his children (like Nico di Angelo) use Stygian Iron. Demigods use weapons made of these metals, because these metals are the only metals by which a monster can be harmed.
- Main article: 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, but is strong enough to cut through a steel door. It is also been mentioned that this metal glows when in weapon form. It can also be melted down to make other weapons, such as bullets, as seen in The Titan's Curse.
Notable Celestial Bronze Weapons
- Riptide - Percy's sword
- Annabeth's Knife - Originally Luke's
- Maimer - Clarisse's spear
- Backbiter (half Celestial Bronze, half Mortal Steel) - Luke's sword
- Aegis - Thalia's shield
- Thalia's spear
- Katoptris - Piper's dagger
- Zeus's Master Bolt
- Hunting Knife - used by the Hunters of Artemis
- Artemis' Knives
- Main article: Imperial Gold
It is unknown where Imperial Gold is mined from, but it is said to be consecrated in the Temple of Jupiter on Capitoline Hill in Rome, as stated by Midas in The Lost Hero, and forged at the Temple of Jupiter at Camp Jupiter. 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- Jason's gladius (destroyed)
- Frank's Spear
- Hazel's Spatha
- Juno's Gladius
- Reyna's dagger
- Reyna's Spear
- Chrysaor's weapons
- Alabaster's sword
- Demeter's sword
- Main article: 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 or are associated with the Underworld). Where weapons made from the other Blessed Metals cause monsters to disintegrate, Stygian Iron absorbs their essence, causing them to either not being able to reform ever again or take a longer time to reform. Like Backbiter, it can also harm mortals. Like Celestial Bronze, it also gives off a faint light, which is dark purple in color.
Notable Stygian Iron Weapons
Although silver is not regarded as a magical metal, it is considered sacred to Artemis (and used by the Hunters of Artemis) and is the only known weapon able to harm lycanthropes (werewolves). It is unknown whether Stygian Iron can also harm them, because, although as a metal of the Underworld it should work against all monsters, demigods, gods, and mortals, Nico was discouraged from using it against Lycaon.