Conversion Table
| gold hallmark
to karats Conversion Table: |
hallmark to kt
250 = 6
333 = 8
375 = 9
417 = 10
500 = 12
583 = 14
|
gold hallmark
to karats
625 = 15
750 = 18
833 = 20
875 = 21
916 = 22
999 or higher = 24
|
| karats
to gold hallmarks Conversion Table: |
kt to hallmark
6 = 250
8 = 333
9 = 375
10 = 417
12 = 500
14 = 583
|
karats to gold hallmarks
15 = 625
18 = 750
20 = 833
21 = 875
22 = 916
24 = 999 or higher
|
The millesimal fineness gold hallmark system is used to denote the purity of gold, platinum or silver alloys by parts per thousand of pure metal by mass in the alloy. Therefore, an alloy containing 50% gold is denoted as "500", 75% gold = "750" etc. Many European countries use millesimal hallmark stamps rather than karat rating stamps.
999 gold hallmark (millesimal) or better, which is close to 100% pure gold = 24 karat gold (kt). 500 millesimal fineness gold hallmark = 12-karat gold = 50% gold alloy. |
