Updated
An anchor is the mark of the Birmingham Assay Office, established in 1773. It tells you where the item was tested. The number beside it tells you the metal: 375 is 9 carat gold, 750 is 18 carat gold and 925 is sterling silver.
| Beside the anchor | Means | Melt per gram |
|---|---|---|
375 | 9 carat gold | $48.90 |
585 | 14 carat gold | $76.28 |
750 | 18 carat gold | $97.79 |
916 | 22 carat gold | $119.44 |
925 | Sterling silver | $1.54 |
950 | Platinum or palladium (the shield shape tells them apart) | $46.85 |
Melt in US dollars. The 950 row is priced as platinum.
London uses a leopard's head, Sheffield a rose and Edinburgh a castle. Older items can carry marks from offices that have since closed, such as Chester and Glasgow. See how to read a UK hallmark.
An anchor in a full hallmark, with a sponsor's mark and a fineness number, means the Birmingham Assay Office tested the item. An anchor on its own is not a hallmark.
Melt value = weight in grams × purity × spot price per gram
Spot prices are quoted per troy ounce, and a troy ounce is 31.1035 grams. Gold spot is $4,055.57, so pure gold is $130.39 a gram.
5 grams of 9 carat gold: 5 × 0.375 × $130.39 = $244.48
Values are in US dollars. Melt values as of 2026-11-09, from spot prices of gold $4,055.57, silver $51.62 and platinum $1,533.98 per troy ounce.
Photograph it, then take a close-up of the stamp. GemstoneAI uses a legible stamp for the metal and gives a first read on what you have and what it may be worth. Your first scan is free.
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Sources: Hallmarking Act 1973, Schedule 2 and the British Hallmarking Council's hallmarking guidance notes.
It is the mark of the Birmingham Assay Office. It shows where the item was tested; the fineness number beside it shows the metal and purity.
If the anchor sits beside a gold fineness number such as 375 or 750, with a sponsor's mark, yes: the Birmingham Assay Office tested it. The number gives the carat.