| Well, as a start, you can look at spot prices for commonly-traded precious metals: http://www.thebulliondesk.com/ The top ones now are rhodium, platinum, gold, iridium, osmium, and palladium (with ruthenium and silver being cheaper). Prices for precious metals are given per troy ounce (31.1g), so you can compare these values to say, price per pound or per kilogram. |