What does 333 mean on jewelry?
Short answer
333: 333 parts per thousand gold (8 karat).
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 | 333 |
| Class | Fineness (purity) mark |
| Gold fineness | 333 parts per thousand (33.3 % gold), 8 karat |
| Legal standard (gold 333) | No statute recorded in our tables; common in trade or by arithmetic |
| Note | Common in Germany; not a UK or Convention standard. |
| Source check | Not checked against a statute: arithmetic or trade usage |
What is 333 worth by weight?
Every gram of a piece stamped 333 holds 0.333 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 $433.20. The working: 10 g → 333 / 1000 → 10 g × 0.333 → 4046.3 USD/ozt ÷ 31.1034768 g/ozt → 3.33 g × 130.0916 USD/g.
Melt value calculator for 333
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 333 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: 8K.
Frequently asked
What does 333 mean on jewelry?
333: 333 parts per thousand gold (8 karat).
Does 333 mean the piece is solid gold?
It means the piece is stamped as 8 karat gold, 333 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 333?
0.333 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
- Hallmarking Act 1973, Schedule 2 (revised text)
- Vienna Convention on precious metals, Technical Decisions Rev. 13 (in force 1 Oct 2026)
- Arithmetic: karats / 24 × 1000 (no external source)
All sources are listed with the method on the sources page.