Gold and silver bullion are purest, readily available, forms of these precious metals. The exact purity is marked on the surface of bullion bars and coins by the manufacturer. This is referred to as a bar’s “stamping” In addition to having a stamped purity a bullion bar must also bear a maker’s mark and guaranteed minimum weight. For this reason, bullion is a popular way for investors to purchase precious metals. As standardized forms of precious metals, bars and bullion coins are easy to buy and sell.
Gold Bullion is typically 99.99% pure and Silver Bullion 99.9% pure. However, if you are discussing bullion with a dealer, these percentages are often shortened to “4 9’s gold” and “3 9’s silver”. Your bar or coin may be stamped 9999, 999.9 or 999,9 or something similar. It is possible for gold to be refined to a higher purity, however this is not required for investment purposes.
Bullion is bought and sold buy its stamped weight, this is usually either in grams or troy ounces (1 troy oz = 31.1g). The stamped weight is the minimum that the bar or coin is expected to weigh. Common metric weights for gold bullion include 5g, 10g, 20g, and 100g bars. Bars sold by the troy oz are 1/2oz, 1oz, 2oz, 5oz and 10oz.
When you cash in your investment the bullion is sent to a refinery. At the refinery it is melted, purified if necessary, and a new bar produced. Because of the risk of fraud in the industry it is unusual for bullion to be sold second hand.