orichalchum

Noun

orichalcum (uncountable)

1. A valuable yellow metal known to the Ancient Greeks and Romans; now sometimes interpreted as referring to a natural alloy of gold and copper, and sometimes treated as a mythical substance.
   • Many walls were coated with metals – with brass, tin and a red ^([sic]) metal, unknown to us, called orichalcum.2008, Jonathan Black, A Secret History of the World, Quercus, published 2008, page 162