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