Orichalcum (also spelled Orachulum) is a fabled mineral with magical properties.
It was created by ancient Atlantean alchemists sometime before 45,000 BCE. The mineral was a commonly known one during the time of ancient Atlantis, having been used to trap sorcerers. After the sinking of Atlantis, it would later be commonly employed among the Thierna Na Oge.
On Prime Earth, the metal has been speculated to have either originated from ancient Atlantis or deep under the mountains of Tibet. Though the Greeks and Romans were able to handle such a metal, medieval alchemist tried duplicating this special mineral to no avail.
When made into metal, Orichalcum has a high resistance to magic, making it suitable for trapping powerful sorcerers. It is also physically resistant against force, able to hold modern Atlanteans in place and Kryptonians. It's piecing abilities can also wound a Kryptonian.
Despite it's resistance, however, it is possible for a very potent source of magic (such as a god) to be able to break through it's resistance.
The dreamscape hero Sandman also stated that when properly fashioned, e.i. in the shape of a whistle or otherwise, said metal can materialize a persons innermost wants and desires making them a thing of reality.
- In DC Universe Online, magic-themed armor and weapons is made of orichalcum and is, instead, considered to be a mystic mineral native to Thierna Na Oge. Felix Faust wears an Orichalcum helmet.