What does 24K mean on jewelry?
Short answer
24 karat gold (999 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 | 24K |
| Class | Fineness (purity) mark |
| Gold fineness | 999 parts per thousand (99.9 % gold), 24 karat |
| Legal standard (gold 999) | United Kingdom, Vienna Convention states, France |
| Source check | Checked against the sources listed below |
What is 24K worth by weight?
Every gram of a piece stamped 24K holds 0.999 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 $1,299.61. The working: 10 g → 999 / 1000 → 10 g × 0.999 → 4046.3 USD/ozt ÷ 31.1034768 g/ozt → 9.99 g × 130.0916 USD/g.
Melt value calculator for 24K
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 24K 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: 999.
Frequently asked
What does 24K mean on jewelry?
24 karat gold (999 parts per thousand).
Does 24K mean the piece is solid gold?
It means the piece is stamped as 24 karat gold, 999 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 24K?
0.999 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
- Hallmarking Act 1973, Schedule 2 (revised text)
- Vienna Convention on precious metals, Technical Decisions Rev. 13 (in force 1 Oct 2026)
- Douane française, table of guarantee marks (2009)
All sources are listed with the method on the sources page.