What does 10K mean on jewelry?
Short answer
10 karat gold (417 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 | 10K |
| Class | Fineness (purity) mark |
| Gold fineness | 417 parts per thousand (41.7 % gold), 10 karat |
| Legal standard (gold 417) | Vienna Convention states, United States |
| Source check | Checked against the sources listed below |
What is 10K worth by weight?
Every gram of a piece stamped 10K holds 0.417 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 $542.48. The working: 10 g → 417 / 1000 → 10 g × 0.417 → 4046.3 USD/ozt ÷ 31.1034768 g/ozt → 4.17 g × 130.0916 USD/g.
Melt value calculator for 10K
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 10K 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: 417.
Frequently asked
What does 10K mean on jewelry?
10 karat gold (417 parts per thousand).
Does 10K mean the piece is solid gold?
It means the piece is stamped as 10 karat gold, 417 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 10K?
0.417 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
- Vienna Convention on precious metals, Technical Decisions Rev. 13 (in force 1 Oct 2026)
- FTC Jewelry Guides, 16 CFR 23.3 (gold)
All sources are listed with the method on the sources page.