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
Synthesis of precious metals Synthesis of precious metals The synthesis of precious metals involves the use of either nuclear reactors or particle accelerators to produce these elements. Ruthenium and rhodium are precious metals produced by nuclear fission, as a small percentage of the fission products. The radioisotopes of these elements generated by nuclear fission with the longest half-lives have half-lives of 373.59 days and 45 days for ruthenium and rhodium, respectively. This makes their extraction from spent nuclear fuel possible, although they must be checked for radioactivity before use. Each kilogram of the fission products of U will contain 63.44 grams of ruthenium isotopes