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The 20K hallmark: meaning, purity & value

20K gold (83.3%) is common in Middle Eastern and South Asian bridal jewelry; equivalent to 833 fineness.

Published May 30, 2026

Quick facts

Metal
Gold
Purity
83.3%
Fineness
833/1000
Karat
20K
Common regions
India, UAE, Japan
Density
16.6 g/cm³
Standard
ISO 9202

Stamps that mean the same thing

This purity may be struck into jewelry as any of: 20K / K20 / 833. The mark differs by country and era, but the metal content is identical.

What 20K tells you

20K gold (83.3%) is common in Middle Eastern and South Asian bridal jewelry; equivalent to 833 fineness.

How to value it

The melt value of a 20K piece is gold spot price × 0.833 × weight (g). A buyer typically deducts 5–15% for assay, refining, and margin, so the cash offer lands just under that figure. Stones and complex settings are usually excluded from the metal weight.

Live calculators: gold karat × weight · item × karat estimates · per-gram hub.

How to check it yourself

  1. Examine the stamp under a 10× loupe — genuine marks are crisp and evenly struck, not doubled or smeared.
  2. Confirm the mark reads 20K or an equivalent such as K20.
  3. Weigh the piece and estimate its volume — the density should land near 16.6 g/cm³ for this alloy.
  4. Photograph it in the Jewelry Identifier app to read the metal, hallmark, and any gemstones from the image.
  5. For a binding result, have an assay office or gemological lab run an XRF purity test.

Sources

  • ISO 9202
  • Trade hallmark references

* Frequently asked

FAQ

Q. Is 20K the same as K20?
A. Yes. 20K, K20, 833 all denote the same material — 83.3% gold. Different markets and eras stamp it differently, but the purity is identical.
Q. How much is 20K worth?
A. Its melt value is the gold spot price × 0.833 × the weight in grams. Buyers then deduct roughly 5–15% for refining and margin, so a quoted buy-back price sits a little below that theoretical figure.
Q. How do I confirm a 20K stamp is genuine?
A. Look at the mark under 10× magnification for crisp, even strikes, cross-check the weight-to-volume ratio against the expected density (16.6 g/cm³ for this alloy), scan it with the Jewelry Identifier app, and — when it matters — have an XRF test done by an assay office or gemological lab.

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