Wavy Diamond Ring with pavé natural diamonds in solid gold worn on the finger, explaining karat stamps for New York readers

Karat Stamps and Hallmarks Explained: What 14K, 585 and 750 Really Mean

A karat stamp tells you how much pure gold is in the metal: karat is measured in parts per 24, so 14K means 14 parts gold out of 24 (about 58.3 percent) and 18K means 18 out of 24 (75 percent). The numbers 585 and 750 say the same thing in parts per thousand. Whether you are buying fine jewelry in New York or ordering it from a studio abroad, understanding these marks, and the US rules behind them, helps you know exactly what you are wearing.

What does karat actually measure?

Karat is a ratio, not a weight. Pure gold is 24 karat. Every karat below that means one twenty fourth of the metal is something other than gold, usually silver, copper, zinc or palladium. These other metals make the alloy harder and give it its color. The math is simple:

  • 24K: 24/24, essentially pure gold.
  • 22K: 22/24, about 91.7 percent gold, often stamped 916.
  • 18K: 18/24, 75 percent gold, stamped 750.
  • 14K: 14/24, about 58.3 percent gold, usually stamped 585.
  • 10K: 10/24, about 41.7 percent gold, stamped 417.

You may notice that 585 is slightly higher than the exact 583. Many makers alloy 14K at 585 parts per thousand to stay safely above the minimum after manufacturing.

If you want to know why those added metals turn gold yellow, rose or white, our explainer on the chemistry of gold alloys goes into the atoms.

Why do some pieces say 14K and others 585?

They are two languages for the same fact. The karat system is traditional in the United States; the millesimal system (parts per thousand) is common across Europe and much of the world. A ring made for an international customer may carry either, or both.

Iconic Cluster Diamond Ring in 14K solid gold with 0.30 ct of natural diamonds

The Iconic Cluster Diamond Ring, for example, is made in 14K solid gold (white, yellow or rose) with 0.30 ct of natural diamonds, which means about 58.3 percent of its metal by weight is pure gold.

What does US law say about gold stamps?

According to MJSA's compliance guide to US marking and stamping regulations, a few rules matter most for shoppers:

  • Tolerance is tight. Under the National Gold and Silver Stamping Act, karat gold may fall below its stamped karat by no more than three parts per thousand, or seven parts per thousand for a piece that contains solder.
  • A trademark must go with the quality mark. If a maker stamps a fineness such as 14K, it must also stamp its federally registered trademark nearby, which shows who is responsible for the gold content.
  • Stamping itself is not required. US law does not force makers to mark precious metal content, so an unstamped piece is not automatically fake.
  • The 10K floor changed. For many years an alloy below 10K could not be called karat gold in the US; MJSA notes that in July 2018 the FTC dropped that threshold, as long as the karat is clearly disclosed.

What is the difference between solid gold, gold filled and gold plated?

This is where the stamps protect you most. MJSA's guide summarizes the FTC definitions:

  • Gold filled (GF): a layer of at least 10K gold bonded to a base metal, making up at least 1/20 of the total metal weight.
  • Gold plate: a far thinner layer of at least 10K gold, with a minimum of 0.175 micron (7 millionths of an inch).
  • Vermeil: gold over sterling silver, at least 100 millionths of an inch thick.

Solid gold, by contrast, is the same alloy all the way through. Scratch it, resize it or polish it for decades and the color underneath is still gold. That is why every piece in this studio is made in solid gold.

3mm Gold Wedding Band with comfort fit, handmade in 14K solid gold

A plain band shows this best. The 3mm Gold Wedding Band, Comfort Fit is 14K solid gold, rounded inside and out, and can be resized or engraved because there is no plating to wear away.

What about hallmarks outside the United States?

A hallmark, in the strict sense, is a mark applied by an independent assay office after testing the metal. In the United Kingdom, for example, independent hallmarking is compulsory for most gold items above a minimum weight. In the US, the system relies on the maker's own quality mark plus its registered trademark. Both approaches aim at the same thing: an honest number you can trust.

Should you choose 14K or 18K?

14K is harder and slightly more resistant to scratches; 18K is richer in color and contains more pure gold. Our guide to 14K vs 18K gold covers the choice in detail.

Wavy Diamond Ring in 18K recycled gold with ethically sourced natural diamonds

The Wavy Diamond Ring is a good example of having both options: it is made in 18K recycled gold and is also offered in 14K, in yellow, rose or white. Margaret Krinetz Fine Jewelry, handmade in Tel Aviv and shipped to New York, lists the exact karat of every piece on its product page.

Frequently asked questions

Is 585 gold real gold?

Yes. 585 is the European way of writing 14K: 58.5 percent pure gold by weight, alloyed with other metals for strength.

How long does delivery to New York take?

Every piece is handmade to order in 4 to 6 weeks, then shipped with DHL Express, usually arriving in New York in 3 to 5 business days. Shipping is free on orders over $1,500.

Does an unstamped piece mean it is not gold?

Not necessarily. US law does not require a quality stamp, so ask the maker for the metal details in writing.

Curious about the science behind your jewelry? Explore our handmade solid gold rings, each one described down to the karat.

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