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
Gold IRA Savings Plan (TSP), and 401(k)s. The four precious metals allowed to be held in an individual retirement account are gold, silver, platinum and palladium, provided they are in the form of IRS-approved coin or bar products. Since gold is the most commonly purchased of the four, the overarching term "gold IRA" is used most often as industry slang to mean a retirement account containing any combination of precious metals. Other terms such as, "precious metals IRA", "silver IRA", "platinum IRA", or "palladium IRA" are also frequently used. Investors often use precious metals as a long-term hedge against inflation, to diversify