What is bullion?
Bullion is precious metal in its bulk, investment form: coins and bars whose value comes almost entirely from their metal content, not from rarity or artistry. It is weighed in troy ounces (31.1 grams — a little heavier than the kitchen ounce) and graded by fineness, the share of the piece that is pure metal. A coin stamped .999 fine is 99.9% pure. Government mints — like the U.S. Mint and the Royal Canadian Mint — strike the best-known bullion coins, while accredited refiners cast and mint bars. Because bullion tracks a global commodity price, it is easy to value on any given day: weight × purity × the spot price.

