Almost every piece of gold jewelry carries a small stamp, usually inside a ring band or near a clasp: 10k, 14k, 18k, sometimes 22k or 24k. That number tells you how much of the metal is actually gold, and it shapes nearly everything else about the piece: its color, how well it stands up to daily wear, and what it costs.
Here is a plain explanation of what each karat means, how to read the stamp, and how to choose between them.
What a Karat Measures
Karat is a measure of purity, counted in 24 parts. Pure gold is 24 karat. A piece marked 18k is 18 parts gold and 6 parts other metals, which works out to 75 percent gold. The other metals, usually silver, copper, zinc, nickel or palladium, are mixed in to make an alloy.
Karat with a k is not the same as carat with a c. Carat is a unit of weight for gemstones, equal to 0.2 grams. A one carat diamond describes how much the stone weighs. A 14 karat ring describes what the metal is made of.
The Common Karats at a Glance
- 24k, 99.9 percent gold. The purest form, a rich orange yellow. It is very soft, so it bends and scratches easily, and it is uncommon in everyday rings in the United States. Often stamped 999.
- 22k, about 92 percent gold. Deep yellow and still soft. Popular for traditional jewelry in South Asia and the Middle East. Often stamped 916.
- 18k, 75 percent gold. A warm, rich yellow with enough strength for fine jewelry. Often stamped 750.
- 14k, about 58 percent gold. The most popular choice in the United States, with a good balance of color, durability and price. Often stamped 585.
- 10k, about 42 percent gold. The lowest karat that can be sold as gold in the United States. Paler in color and the hardest wearing of the group. Often stamped 417.
How Karat Changes Color
The more gold in the alloy, the deeper and warmer the yellow. Set an 18k ring beside a 10k ring and the difference is easy to see. The metals mixed in also decide the color:
- Yellow gold is alloyed mostly with silver and copper.
- Rose gold uses a higher share of copper, which gives it the pink tone.
- White gold is alloyed with white metals such as palladium or nickel, and is usually plated with rhodium for a bright white finish. That plating wears over time, so white gold is replated when it starts to look yellowish.
Durability and Everyday Wear
Pure gold is soft. Alloy metals make it harder, so as the karat goes down, the metal generally resists scratches and dents better. That is why 14k is such a common choice for rings and bracelets worn every day, while 18k and higher often go into pieces that see lighter wear, or to people who love the richer color and accept a few more marks over time.
Every karat will scratch eventually. Fine scratches build into a soft patina that many people come to love, and a jeweler can polish a piece back to a high shine when it is time.
Does Gold Tarnish?
Pure gold does not tarnish or rust. The other metals in an alloy can react with sweat, chlorine, sulfur and household chemicals, though, so lower karat gold, which carries more alloy, can occasionally darken or discolor a little. A gentle wash in warm water with a drop of mild dish soap and a soft brush usually brings it back.
In Hawaii, chlorine is the one to watch. Pool and hot tub water is hard on gold alloys over time, so take rings and bracelets off before you swim in a pool. Salt water and sunscreen mainly leave a film that dulls the shine, so rinse your jewelry in fresh water after a beach day. For bangles and other engraved pieces, our heirloom jewelry care guide goes into more detail.
What Karat Does to the Price
Gold is priced by weight and purity, so the same design costs more in a higher karat. An 18k ring holds noticeably more gold than the same ring in 14k. The design and the work at the bench are the same either way, so the difference in price comes down to the metal.
Solid Gold, Gold Plated, Gold Filled and Vermeil
Not everything that looks like gold is gold all the way through. These terms show up on labels and listings, and they mean very different things:
- Solid gold means the whole piece is a gold alloy of the stated karat. It can be resized, repaired and polished for decades.
- Gold plated means a thin layer of gold over a base metal such as brass or sterling silver. It looks the same when new, but the layer can wear through with time, especially on rings and bracelets that rub against things.
- Gold filled has a much thicker layer of gold bonded to a base metal. Under United States guidelines the gold layer must be at least 10k and make up at least one twentieth of the total weight. It lasts far longer than plating, but it is still not solid gold.
- Vermeil, said ver-MAY, is sterling silver coated with gold that is at least 10k and at least 2.5 microns thick, under the same guidelines.
None of these is a bad choice, and gold plated sterling silver is a popular way to get the look of gold at a lower price. They are simply different things, and the price should match what you are buying.
How to Read the Stamp
Look inside a ring band, on the back of a pendant, or near the clasp of a chain or bracelet. The common marks:
- 10K, 14K, 18K, 22K or 24K, sometimes written KT. KP stands for karat plumb, meaning the gold meets its stated karat in full.
- 417, 585, 750, 916 or 999 give the gold content in parts per thousand, the system used in much of the world. 585 is 14k and 750 is 18k.
- GP, GEP, HGE, RGP or GF mean gold plated, gold electroplated, heavy gold electroplate, rolled gold plate and gold filled. Any of these tells you the piece is not solid gold.
- A maker's mark often sits beside the karat stamp. In the United States, a piece stamped with its karat should also carry the trademark of the company that stands behind it.
A stamp is a good start, but stamps can be worn away, wrong or faked. If a piece matters to you, a jeweler can test the metal.
Which Karat Should You Choose?
- For an everyday ring or bracelet: 14k is the usual sweet spot of color, strength and price.
- For a richer color, or a piece that sees lighter wear: 18k.
- For the hardest wearing and lowest cost: 10k, keeping the paler color in mind.
- For sensitive skin: nickel is the usual cause of reactions, and some white gold alloys contain it. Ask what the alloy is, or choose yellow gold or a palladium white gold.
If you have inherited gold jewelry and are not sure what to do with it, our guide to inherited jewelry is a good place to start. And if you are choosing a metal for a custom piece, get in touch and we can talk through the options.
