World Precious Metal Purity Marks

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