Adamant
Adamant is any especially hard substance, whether diamond, other gem or metal. Both adamant and diamond derive from the Greek word adamas, meaning untameable.
Since diamond is now used exclusively for the hardest gem, adamant has mostly poetic or figurative use. As an increasingly archaic word, it - and its adjectival form adamantine - is especially often seen in fantasy fiction. For instance, in J. R. R. Tolkien's The Lord of the Rings, Galadriel's ring Nenya is also named the "Ring of Adamant".
Adamantium is the strongest metal (or substance?) known in the Marvel Comics universe. This metal alloy is malleable in its molten state, but is nearly indestructable once cooled. It is used as the key component in many of its characters' equipment, including Captain America's shield and Wolverine's claws.
Adam Adamant Lives was a BBC television series in the 1960s.
The Adamant Music School is a piano school located in the village of Adamant, Vermont just north of Montpelier. The Adamant Press is also located in the village.
The Adamant was an iron barque (sailing ship) that brought immigrants to New Zealand in the late 19th century.Adamantium