Bullion refers to gold and silver officially recognized as being at least 99.5% pure and is in the form of bars or ingots rather than coins.

The gold bars — which sell out very quickly — go for about 2% more than the spot price. Costco could be selling up to $200 million worth of its 1-ounce gold bars and packs of 25 silver coins ...

Costco had 100-gram gold bars for $7,600. ... Costco has been selling gold and silver at a rate of $200 million per month, ... the two-square-inch slabs cost as much as a high-mileage used car.