What does 15ct mean on jewelry?
Short answer
15 karat gold (625 parts per thousand).
A mark is a statement, not proof: it can be forged or struck on a plated piece. An assay confirms it (touchstone and acids, or X-ray fluorescence).
The stamp in detail
| Item | What the tables say |
|---|---|
| Stamp | 15ct |
| Class | Fineness (purity) mark |
| Gold fineness | 625 parts per thousand (62.5 % gold), 15 karat |
| Legal standard (gold 625) | United Kingdom, 1854 to 1932 only |
| Source check | Checked against the sources listed below |
| Date clue | Not before 1854. In the UK, 15 carat gold was hallmarked from 1854 to 1932. |
What is 15ct worth by weight?
Every gram of a piece stamped 15ct holds 0.625 g of fine gold, if the stamp is accurate. Multiply that by the spot price of gold to get the melt value. It is the floor, what the metal is worth if melted, not what a buyer will pay and not an appraisal.
Example, clearly not live: 10 g at the example price of $4,046.30 per troy ounce (snapshot of 2026-11-10) is $813.07. The working: 10 g → 625 / 1000 → 10 g × 0.625 → 4046.3 USD/ozt ÷ 31.1034768 g/ozt → 6.25 g × 130.0916 USD/g.
Melt value calculator for 15ct
Enter a weight and a stamp to see the sum.
Today's spot price: LBMA precious metal prices, Kitco live gold or your own dealer's quote. This page never contacts a price service.
What 15ct can be mistaken for
Pieces that look like gold and are not:
- plated and gold filled
- pinchbeck and gilt brass
- silver gilt (vermeil)
What a stamp cannot settle: The metal. Colour is not a fineness, and a mark can be forged.
What settles it:
- Magnet: if it sticks, it is not solid gold (not sticking proves nothing).
- Jeweller: touchstone and acids, or X-ray fluorescence, in two minutes.
Related stamps
Other ways the same fineness is stamped: 625.
Frequently asked
What does 15ct mean on jewelry?
15 karat gold (625 parts per thousand).
Does 15ct mean the piece is solid gold?
It means the piece is stamped as 15 karat gold, 625 parts per thousand. A mark is a statement, not proof: it can be forged or struck on a plated piece. An assay confirms it (touchstone and acids, or X-ray fluorescence).
How much fine gold is in a piece stamped 15ct?
0.625 g of fine gold per gram of metal, if the stamp is accurate. Melt value is that weight times the spot price. It is not an appraisal.
Sources
- Arithmetic: karats / 24 × 1000 (no external source)
- National Gold and Silver Stamping Act, 15 U.S.C. § 294
- The Goldsmiths' Company Assay Office, History of hallmarking
All sources are listed with the method on the sources page.