Fineness Marks Explained
Why jewellery uses numbers such as 375, 585, 750, 916, 925 and 950.
Parts Per Thousand
Millesimal fineness expresses the amount of precious metal in an alloy out of 1,000 parts. A 750 gold mark means the alloy meets the 750 parts-per-thousand gold standard; a 925 silver mark means 925 parts-per-thousand silver.
Why Fineness Is Better Than Colour
Colour is not a reliable test of metal content. A plated base-metal item can look gold, and platinum, silver and white gold can all look broadly white. A recognised hallmark gives independently tested fineness information.
Common Numbers Customers See
- 375 - commonly 9ct gold
- 585 - commonly 14ct gold
- 750 - commonly 18ct gold
- 916 - commonly 22ct gold
- 925 - sterling silver
- 950 - commonly platinum
A Fineness Stamp vs a Hallmark
A single number stamped on jewellery is not necessarily a full recognised hallmark. Context, additional marks and the origin of the item matter. When authenticity is important, the item should be inspected rather than judged from one stamp.
Frequently Asked Questions
Can a fake item carry a fineness number?
Yes. Testing may still be needed.
Does 925 mean white gold?
No. 925 most commonly indicates sterling silver.
What does 950 usually mean?
It is commonly encountered on platinum, though the surrounding hallmark shape and other marks help identify the metal.
Ask Gold Factory If you would like help applying any of this information to a real piece of jewellery, visit us at 294 Farnham Road, Slough, SL1 4XL, call 01753 536800 or contact us through www.goldfactory.co.uk. Jewellery can vary, so our team can explain the options for the actual item you are considering. |
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