Dissambiguation: This page is for the DC's metal alloy called Promethium. Not to be confused with Marvel's Promethium nor with real life Promethium (element 61).
In the DC universe, Promethium was first developed by Dayton Labs, a company owned by Steve Dayton. It was a metal named after the Titan Prometheus. He was being punished by Zeus for giving mankind fire and had a giant eagle eat his liver on a daily basis, but since he was a Titan, he grew another by the next day. The metal had regenerative properties which could be used in metallic creations mended themselves, or potentially make highly destructive weapons. In other relativity Promethium can be virtually indestructible depending on continuity, the metal itself comes in two variants which are as follows:
The radioactive variant can absorb, emit and/or magnify raw energy, able to generate larger if not unlimited quantities of it for various purposes. In the 31st century Volatile Promethium is used as a self generating power source. It's been known to have mutagenic properties as well, often activating latent metagene's or mutating those around it into abominations like The Hybrid. Through controlled creation, it can be used to create artificial superpowered beings like the ReCombatants. A certain mercenary utilizes it in his weapons and chain-mail body armor, able to handle and is possibly enhanced by it's radioactivity due in part to his metahuman physiology.
Non-radioactive elemental variant which by it self boasts an impressive durability to damage and abrasion. Ronnie once stating not even superman could break base promethium when he transmuted the element to restrain Gamemnae, once bonded with other metals like Titanium, Vanadium or molybdenum-steel to make all but invincible. The extra-dimensional entity Access once likened the materia's toughness to Adamantium, a great many components comprising the bionic human hero Cyborg; are composed of it as is the Kevlar body armor worn by Arsenal.