Troy weight A grain is 20 mites, a mite is 24 droits, a droit is 20 perits, a perit is 24 blanks. In Scotland, the Incorporation of Goldsmiths of the City of Edinburgh used a system in multiples of sixteen. ("See Assay-Master's Accounts, 1681–1702, on loan from the Incorporation to the National Archives of Scotland".) Thus, there were 16 drops to the troy ounce, 16 ounces to the troy pound, and 16 pounds to the troy stone. The Scots had several other ways of measuring precious metals and gems, but this was the common usage for gold and silver. The Pound was
Bullion precious metals. Bullion Bullion is gold, silver, or other precious metals in the form of bars or ingots. Typically, bullion is used for trade on a market. The word "bullion" comes from the old French word "bouillon", which meant "boiling", and was the term for the activity of a melting house. The value of bullion is typically determined by the value of its precious metals content, which is defined by its purity and mass. To assess the purity of gold bullion, the centuries-old technique of fire assay is still employed, together with modern spectroscopic instrumentation, to accurately determine its quality