What does 585 mean on gold jewelry?

The short answer: 585 is the fineness mark for 14 karat gold

Numbers such as 375, 585 and 750 are millesimal fineness marks. They express the precious metal content in parts per thousand, so 585 means 585 parts of gold in every 1,000 parts of the alloy, or 58.5 percent.

Karats express the same idea in 24ths. Pure gold is 24 karat, and a 14 karat piece is 14 parts gold mixed with 10 parts of other metals. Fourteen divided by twenty-four is about 0.583, and 585 is the standard fineness number used for 14 karat gold. The remaining 41.5 percent is usually a mix of metals such as silver, copper or zinc, chosen for color and hardness.

In hallmarking systems such as the United Kingdom’s, the number is a minimum. UK government guidance explains that the fineness mark shows the least amount of precious metal the alloy must contain, so a properly hallmarked 585 item should contain at least 585 parts of gold per 1,000.

Where you will see 585 and how it sits next to other marks

On rings, look inside the band. On chains and bracelets, check the clasp, the jump ring next to it or a small tag. On earrings, the mark is often on the post or the butterfly back. The stamp can be tiny and partly worn, so a loupe or a zoomed phone photo in good light helps.

You may find 585 on its own, next to a karat mark such as 14K, or as part of a fuller hallmark. In the United States, gold is commonly marked in karats, and the Federal Trade Commission advises buyers to look for the name or registered trademark of the company that stands behind the karat mark. A full UK hallmark has three compulsory parts: a sponsor’s or maker’s mark, the fineness mark, and the mark of the assay office that tested the item.

What a 585 stamp does not prove on its own

A stamp is a claim, not a test result. A lone 585 with no maker’s mark, a mark that looks freshly struck on a worn piece, or a number that does not match the weight and look of the item are all reasons to check further.

It also matters what surrounds the number. Marks such as GF, GP, HGE or RGP point to gold-filled or gold-plated items, where a layer of gold covers a base metal. The FTC describes gold filled and rolled gold plate as a layer of at least 10 karat gold mechanically applied to a base metal, so a ring marked 14K GF is not solid 14 karat gold.

• Look for a maker’s mark or trademark alongside the fineness number.
• Check for plating abbreviations such as GF, GP, HGE or RGP.
• Compare the stamp with the item’s wear, color and weight.
• For anything valuable, ask a jeweler or assay office to test the metal.

How 585 compares with 375, 750 and other fineness marks

Every fineness number works the same way, so once you understand 585 you can read the others. A higher number means more gold in the alloy, and a lower number means more of other metals. That trade-off affects more than value. Higher-karat gold, such as 750 or 916, is richer in colour and softer, so it scratches and bends more easily. Lower-karat gold, such as 375, is harder and paler, and it costs less for the same weight.

That is why 585 is a popular middle ground for rings and chains that are worn every day: it has a good share of gold while staying reasonably hard. You will also meet a few variations. Some older pieces, particularly from the former Soviet Union, carry 583 instead of 585, which also corresponds to roughly 14 karat. Some American pieces carry only 14K with no number at all. The meaning is the same; what you are reading is the claimed share of gold.

• 375: 9 karat, 37.5% gold.
• 585 (or 583 on some older pieces): 14 karat, about 58.5% gold.
• 750: 18 karat, 75% gold.
• 916: 22 karat, about 91.6% gold.
• 999: 24 karat, fine gold.

585 in yellow, white and rose gold

The colour of a gold piece comes from the other metals in the alloy, not from the amount of gold. A 585 ring can be yellow, white or rose. Yellow gold usually balances silver and copper, rose gold uses a larger share of copper, and white gold uses whitening metals such as palladium or nickel. In each case, the 585 stamp means the same thing: at least 585 parts of gold per thousand, if the mark is genuine.

White gold has one extra detail worth knowing. Many white gold pieces are plated with rhodium, a bright white metal, to make the surface whiter. That plating wears over time, and a slightly yellowish tone showing through on a well-worn white gold ring is often just the gold alloy underneath, not a sign of fake metal. A jeweler can replate it if you prefer the whiter finish.

A worked example: estimating the metal in a 585 chain

Say you have a chain stamped 585 next to a maker’s mark, and it weighs 12.4 grams on an accurate kitchen or jewelry scale. It has no stones, and the clasp is marked too, so you treat the whole weight as 585 gold. Multiply 12.4 by 0.585 and you get about 7.25 grams of pure gold.

Next, look up a current gold price per gram from a source you trust, in your own currency. Gold prices are often quoted per troy ounce, and one troy ounce is about 31.1 grams, so divide an ounce price by 31.1 to get a price per gram. If, purely as an illustration, the price were 100 per gram, the chain’s metal-only value would be about 725 in that currency. That figure is your reference point, not an offer: a buyer who melts gold will usually pay less, and a well-made or collectible chain may be worth more than its metal.

Common mistakes when reading a 585 stamp

A few mix-ups come up again and again. Avoiding them saves money and disappointment when you sell, buy or insure a piece.

• Reading 585 as 58.5 karat or as 5.85 grams. It is a share of gold in parts per thousand, nothing else.
• Ignoring letters next to the number. 585 with GF, GP or HGE describes a gold layer, not solid gold.
• Weighing stones and non-gold parts as gold. Subtract them, or ask a jeweler to estimate them, before you calculate.
• Assuming a worn white gold ring is fake because it looks yellowish. The rhodium plating may simply have worn.
• Treating a melt value estimate as a selling price. Buyers deduct refining costs and their margin.

What 585 means for value

Because 585 tells you the share of gold, it lets you estimate the metal content. Multiply the weight of the gold parts by 0.585 to get the approximate weight of pure gold. For example, 10 grams of 585 gold contains about 5.85 grams of pure gold. Multiply that by a current gold price per gram and you have a rough melt value.

Keep two limits in mind. Melt value covers only the metal, so it leaves out stones, craftsmanship, brand and condition. And buyers who melt gold usually pay less than the full melt value to cover refining and their margin, so compare offers against your own estimate rather than taking the first number you hear.

How to check a piece marked 585

Start with a clear, close photo of the stamp and any marks around it, then look them up in a hallmark reference. Weigh the item on an accurate scale and note any stones or non-gold parts. If the piece matters to you, a jeweler can test the metal, for example with acid testing or X-ray fluorescence, and a qualified appraiser can value it for insurance or sale.

CaratAI can help you organize those first observations from a photo, so you arrive at the jeweler with the marks, the weight and your questions already noted.

Frequently asked questions

Is 585 gold real gold? A genuine 585 mark means the alloy is about 58.5% gold, so the piece is real 14 karat gold, not pure gold. The mark itself is a claim; a maker’s mark, an assay hallmark or a professional test makes it more reliable.

Is 585 the same as 14K? Yes. 585 is the fineness number used for 14 karat gold, and both describe about 14 parts gold in 24. Some older pieces use 583 for the same standard.

Is 585 better than 750? Neither is better in every way. 750 (18 karat) contains more gold and has a richer colour, while 585 is harder and costs less for the same weight. Many people choose 585 for pieces they wear every day.

Does 585 gold tarnish? Gold itself does not tarnish, but the other metals in a 585 alloy can darken slightly over many years, especially with exposure to chemicals. A gentle clean with mild soap and warm water is usually enough.