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Karat vs fineness: what 10k, 14k, 18k, and 22k actually mean
24k is the whole pie. 14k is a little more than half gold. The stamp is a claim. The test is the truth. Weight without karat is a guess.
Gold jewelry is almost never “gold” the way an eagle is gold.
An American Gold Eagle is 22k, and even that is a known alloy with a known weight. A “gold chain” from a mall can be 10k, 14k, gold filled, or plated pot metal with a $ stamp that was feeling ambitious.
The pie chart
24 karat means as pure as jewelry talk gets — 100% of the pie is gold, give or take refining reality.
- 22k — about 91.7%. Many coins. Some high jewelry.
- 18k — 75%
- 14k — 58.3%
- 10k — 41.7%. Still gold. A lot of it is not gold.
If we pay you 10k prices on a 14k stamp that tested 10k, we are not being mean. The acid does not care what the stamp wanted to be.
Tiny gold, use gold, 10k/14k novelties is the cousin of this article.
Fineness is the same idea in thousandths
.999 fine is basically 24k talk. .916 is 22k talk. .750 is 18k. European jewelry often stamps fineness instead of karat. Same pie, different dialect.
Why the stamp is not enough
Stamps get faked. Old repairs add solder that is not the same karat. A 14k chain with a steel clasp is not 14k all the way through. We test. We weigh. We subtract the obvious non-gold. Testing in front of you.
Gold filled and plated are not karat math
If it says GF, HGE, or “gold plated,” stop doing karat arithmetic. You do not have a 14k bar. You have a skin. Gold filled vs plated vs solid.
What to do before you come in
Do not file it up at home. Do not acid-test it on the kitchen table. Bring it. Watch the test. Ask them to write karat and weight on the ticket. If they will not, leave.
Part of the coin shop counter wiki · visitors & collectors · NumisQ Learn