Two ways to describe gold content
Karat notation divides an alloy into 24 parts. Millesimal notation expresses a proportion out of 1,000. Thus 18K corresponds to 750, or 75% gold. The FTC explains karat quality marks and the distinction between gold alloys and plated products.
The table below is a sorting aid. Manufacturing marks, wear, repairs and mixed components can complicate identification. Record what you see rather than deciding that an item is definitely genuine from a number alone.
| Common mark | Nominal gold content |
|---|---|
| 10K / 417 | About 41.7% |
| 14K / 585 | About 58.5% |
| 18K / 750 | 75% |
| 22K / 916 or 917 | About 91.6–91.7% |
| 24K / 999 | About 99.9%; verify the stated fineness |
Reference sources: FTC — Precious metal markings
Read the letters beside the number
A mark such as GP, GF or RGP changes the interpretation. These are associated with plated or layered construction rather than a matching gold alloy throughout the object. Do not value the entire weight of a plated item as though it were the karat stamped beside the plating abbreviation.
Photograph the whole mark and its location. A close crop that shows only “14K” may hide other letters that matter. If a chain has several marked parts, photograph each of them: the clasp and pendant can provide different information. Keep uncertain items in their own group for inspection.
What if the mark is missing or difficult to read?
An absent or worn mark is a reason to ask for testing, not an automatic decision to discard the item. Use a magnifier and good light; avoid scraping, filing or applying household chemicals to reveal a stamp. If you cannot read it, leave the description open.
A magnet is not a complete gold test. A reaction may come from a component, and a lack of reaction does not establish gold purity. Likewise, color alone is not enough to distinguish gold from other materials. Ask the buyer which tests are appropriate and whether any proposed test could leave a mark.
Use the marking to understand an offer
Once purity is verified, ask for the eligible metal weight and the price basis. For example, 20 grams of confirmed 18K metal contains a theoretical 15 grams of fine gold. This is a material calculation only; it is not the amount a buyer has promised to pay.
For a mixed group, request separate weights or explanations for the different purity categories. Bring the pieces to Iron Eagle Reserve at 174 E Flagler St or send photos first. The gold-price guide explains the next step: moving from a reference metal value to an actual offer after inspection.
Your evaluation checklist
- Photograph complete marks, including letters.
- Check pendants, chains and clasps separately.
- Keep plated or uncertain items apart from clearly marked groups.
- Ask how test results and metal weight affect the offer.
Frequently asked questions
Does 750 mean 18K gold?
750 expresses 750 parts per thousand, which corresponds to 18K. The actual piece still needs verification; the mark alone is not proof of authenticity.
Is 585 gold the same as 14K?
585 is a common millesimal mark associated with 14K gold. It describes nominal fineness rather than a guaranteed test result for an unknown item.
Can gold without a stamp be evaluated?
Yes. Tell the buyer that no readable mark is present and ask how the material will be identified before pricing it.
Request an evaluation of your items
174 E Flagler St, Miami · Monday–Saturday, 9AM–8PM. English and Spanish available. Final offers are confirmed after examining the item.
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