copper? wo fur?
iridium, platinum, ruthenium, osmium... sure.
but copper?
Copper is often ignored when everybody is going for the Inca gold. Just as lead and zinc are ignored when going for British silver. The glitter and glory is in the noble metals, but the secret is in the base metals. The big money will be in Roman iron and Boeing aluminum, but Trojan copper will suffice, and will be found in quantity enough to pay. Besides, copper makes better spear points than platinum does.