What is 18K gold?
18K gold is 75% pure gold. The other 25% is a mix of other metals — usually copper, silver, sometimes zinc or palladium — added to make it strong enough to wear.
That's it. That's the whole definition.
The "K" stands for karat, which measures gold purity on a 24-point scale. 24K is 100% pure gold. 18K is 18/24 — three-quarters pure. 14K is 14/24, or 58.3% pure. 10K is 41.7% pure and barely qualifies as gold jewelry under US law.
Pure gold (24K) is too soft to wear. It bends, dents, and warps. That's why every piece of gold jewelry you've ever owned is technically an alloy — a mix. The question is just how much gold is in the mix.
What does "750" mean?
"750" is the European hallmark for 18K gold. It means 750 parts per thousand are pure gold. Same thing as 18K, just written as a number instead of a karat.
If you flip over an 18K piece and see "750" stamped somewhere — clasp, inner band, post — that's the legal proof of purity. In most of Europe, hallmarking is government-regulated. A "750" stamp means an independent assay office verified the gold content.
In the US, hallmarking isn't regulated the same way, which is part of why so many "gold" pieces here are vague about what they actually are. We hallmark every piece "750" or "18K" because we want the proof on the metal itself, not just on a tag.
Why 18K is the global standard for fine jewelry
Three reasons:
Color. 18K has the rich, warm yellow most people picture when they think of gold. 14K looks paler and slightly washed out because there's more alloy metal in it. 10K can look almost greenish.
Durability with integrity. 18K is hard enough to wear every day — earrings, rings, daily-wear chains — without bending. It's softer than 14K, yes, but the difference is marginal for normal wear and meaningful for color.
Resale and inheritance. 18K holds value because it has more actual gold in it. A 14K piece is worth roughly 78% of what an equivalent-weight 18K piece is worth in raw material. This matters when you're buying something to keep, gift, or pass down.
Why most US brands sell 14K instead
The honest answer: margin.
14K costs the brand meaningfully less to produce because it contains less gold. But it's typically priced only slightly lower than 18K would be. The markup gap is the brand's profit.
There's a secondary reason the industry uses to justify it — 14K is harder, so it's "better for everyday." This is technically true and practically irrelevant. 18K is plenty hard for everyday wear. The Italians, the French, and most of the world have been wearing 18K daily for centuries without their jewelry falling apart.
The real reason 14K dominates the US is that it was the legal floor for a long time and brands built their supply chains around it. Now the supply chains exist and the margins are good, so 14K is what gets sold.
FAQ
Is 18K gold real gold? Yes. 18K gold is 75% pure gold mixed with 25% other metals to add strength. It's real, solid gold — the global benchmark for fine jewelry.
Does 18K gold tarnish? No. Real 18K gold doesn't tarnish, rust, or oxidize. It can dull slightly from oils and lotions but cleans up easily with mild soap and water.
What does the "750" stamp mean? "750" is the European hallmark for 18K gold. It means 750 out of 1000 parts are pure gold — the same thing as 18K, just expressed as parts per thousand.
Can you shower in 18K gold? Yes. Solid 18K gold is fine in water. Avoid chlorinated pools and harsh soaps to keep it looking its best, but daily showering won't damage it.
Is 18K gold hypoallergenic? Yes. 18K typically doesn't contain nickel (which is the common allergen). Pieces alloyed with copper, silver, or palladium are generally safe for sensitive skin.
