While not a fully comprehensive list, you’ll find the vast majority of marks used in jewelry making today.
Metal Alloy |
US Purity Marks |
Purity Marks in Other Countries |
Gold | 10K, 14K, 18K, 22K | 8K, 9K, 12K, 14K, 18K, 22K 333, 375, 416, 500, 585, 625, 750, 916 |
Platinum | PT950, 950PT, 950PLAT, PT900, 900PT, 900PLAT, PT999, PT850, PLAT, PLATINUM | PT950, 950PT, 950PLAT, PT900, 900PT, 900PLAT, PT999, PT850, PLAT, PLATINUM, Pt850, Pt900, Pt950, Pt999, PT |
Sterling Silver | .925 Sterling Sterling Silver |
STG SLV, STG Silver, Sterling Silver, .925, & various pictoral marks |