Troy weight Troy weight Troy weight is a system of units of mass customarily used for precious metals and gemstones. One troy ounce (abbreviated "t oz" or "oz t") is equal to exactly , (or about 1.0971 oz. avoirdupois, the "avoirdupois" ounce being the most common definition of an "ounce" in the US). There are only 12 troy ounces per troy pound, rather than the 16 ounces per pound found in the more common avoirdupois system. The avoirdupois pound has 7000 grains whereas the troy pound has only 5760 grains (i.e. 12 × 480 grains). Both systems use the same grain defined
Hierarchy of precious substances Hierarchy of precious substances In popular culture, sets of precious substances may form hierarchies which express conventional perceived relative value or merit. Precious metals appear prominently in such hierarchies, but as they grow, gems and semi-precious materials may be introduced as part of the system. The sequences can provide interesting examples of the arbitrariness of semiotic signs. Jubilees have a hierarchy of years: silver (25 years), ruby (40 years), golden (50 years), diamond (60 years), and platinum (70 years). Wedding anniversaries extend the jubilee hierarchy with various sequences of substances filling in many of the gaps between the same major