Apothecaries' system between actual and nominal weight. In the 19th century, most European countries or cities still had at least a "commercial" or "civil" system (such as the English avoirdupois system) for general trading, and a second system (such as the troy system) for precious metals such as gold and silver. The system for precious metals was usually divided in a different way from the commercial system, often using special units such as the carat. More significantly, it was often based on different weight standards. The apothecaries' system often used the same ounces as the precious metals system, although even then the
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