Use this handy guide to quickly calculate the true gold value of jewelry with simple arithmetic. No more guessing at percentages or overpaying for your scrap gold jewelry Markings: K, Karat KP, Karat Plumb (exact amount of gold) K.P., Karat Plate GF, Gold Filled GS, Gold Shell GP, Gold Plated GEP, Gold Electroplated HGE, Heavy Gold Electroplate Vermeil, Sterling silver that is gold filled or gold plated. Pave, a setting covered with tiny stones. 31.10348 grams = 1 troy ounce (ozt) 1 troy ounce = 1.09714 avoirdupois ounce 28.3495 grams = 1 avoirdupois ounce 20 pennyweights = 1 troy ounce Gold is measured in troy ounces, which are roughly 10% heavier than avoirdupois ounces.