ὀρείχαλκος

Etymology
Looks like the dative singular of +, however the same way Latin has connected the first part as  to  this is also a folk-etymology and the first part is rather , making a tautological compound.

Noun

 * 1) brass made from yellow copper ore; an alloy of copper and "mock silver" (presumably zinc)
 * 2) orichalcum, a natural or mythical valuable alloy of copper and perhaps gold
 * 1) orichalcum, a natural or mythical valuable alloy of copper and perhaps gold