Which metal is the most valuable?

While gold and platinum are the famous precious metals, rhodium is typically the most valuable by price per gram. A silvery-white member of the platinum group, rhodium is extremely rare — far scarcer than gold — and most of it is mined as a byproduct in South Africa. Its main use is in catalytic converters, which reduce harmful emissions from vehicles, and demand from the auto industry can send its price soaring, at times several times higher than gold. Other extremely valuable metals include platinum, palladium, and iridium. Even rarer specialty elements like certain isotopes can be priceless, but among traded metals, rhodium usually leads.