Adamantine is described as an enchanted metal used by Greek heroes and gods. It isn't mentioned in the main series. (Like Celestial Bronze, Imperial Gold, and Stygian Iron.) Though is mentioned in Percy Jackson's Greek Gods. The known adamantine weapons are also made of Imperial Gold.
Adamantine is supposedly an indestructible metal that glitters translucent white, mixed with light green, sort of like a "cross of silver and diamonds."
Notable Adamantine Weapons
- Perseus's Sickle (half-Adamantine, half-Imperial Gold)
- Hermes's Sword (half-Adamantine, half-Imperial Gold)
Notable Adamantine Items
- Hera's Throne (pure Adamantine) used for restraining her