Most often the markings and stamps on jewelry will not only tell you what kind of metal was used, but who made it and what country it came from. The maker’s stamps and hallmarks can be identified using a jeweler’s 10x or 20x loop.
Even then, many marks are just to small or irregular to clearly identify. Most often the marks on your jewelry will also determine value. There are literally millions of different marks used to identify all precious metal items.
The United States Government does not require jewelers to hallmark their precious metal jewelry. However, nearly all United States fine jewelry comes stamped to assure the quality of the metal. The purity of the metal is one of the major value indicators. Many jewelry buyers feel more comfortable purchasing pieces that are hallmarked.
IMPORTANT NOTE: A hallmark can also give a buyer a false sense of security since unscrupulous jewelers or street vendors can stamp their own hallmarks on poor quality jewelry to pass it off as the real thing. Gold plated copper, brass or any non-magnetic material can be used to fool the untrained.
*HALLMARKS & STAMPS = PURITY OF METAL
*(There is Yellow, White, Rose & Green Gold)
333, 8K, 8kt = 8 karat gold or 33.3% pure gold
375, 9K, 9kt = 9 karat gold or 37.5% pure gold
417, 10K, 10kt = 10 karat gold or 41.7% pure gold (10 parts gold – 14 parts other metals)
585, 14K, 14kt = 14 karat gold or 58.5% pure gold (14 parts gold – 10 parts other metals)
667, 16K, 16kt = 16 karat gold or 66.7% pure gold
750, 18K, 18kt = 18 karat gold or 75.0% pure gold (18 parts gold – 6 parts other metals)
833, 20K, 20kt = 20 karat gold or 83.3% pure gold
875, 21K, 21kt = 21 karat gold or 87.5% pure gold
917, 22K, 22kt = 22 karat gold or 91.7% pure gold
958, 23K, 23kt = 23 karat gold or 95.8% pure gold
999, 24K, 24kt = 24 karat gold or 99.9% pure gold
*10 or 14kt GF = Gold Filled
*10 or 14kt GP = Gold Plated
* = Vermeil = Gold and silver blend
900 = 90% pure silver (10% alloy metals)
925, STR, Sterling, Ster = 92.5% pure silver (7.5% other metals)
999 = 99.9% pure silver
850plat, 850pt = 85% pure platinum
90plat, 900plat, 900pt = 90% pure platinum
950plat, 950pt, Plat = 95% pure platinum
850pall, 850pd = 85% pure palladium
900pall, 900pd = 90% pure palladium
950pall, 950pd = 95% pure palladium