Gold price per gram by karat

Karat measures parts of gold out of twenty four. 18k is 18 parts gold and 6 parts alloy, which is 75% pure. 14k is 58.33%, 10k is 41.67%. The value per gram is simply the fine gold price multiplied by that fraction, which is why the table below is a straight line rather than anything mysterious.

The trade rounds some of these. 22k is treated as 91.67% and 24k as 99.9% rather than a theoretical 100%, because absolutely pure gold is too soft to work.

European and most modern pieces carry a three digit fineness: 375 for 9k, 417 for 10k, 585 for 14k, 750 for 18k, 916 for 22k, 999 for 24k. US pieces more often use 10K, 14K, 18K directly.

A missing stamp does not mean the piece is fake. Older jewellery, and anything that has been resized, often lost its hallmark. Any buyer will test rather than trust the stamp anyway.

The karats are not interchangeable choices; each dominates a particular market for a reason. 9k is a British and Commonwealth convention at the affordable end. 10k is the American floor, common in class rings and hard wearing chains. 14k dominates US jewellery because it balances colour against durability.

18k is the European and luxury standard, and where most branded fine jewellery sits. 22k and 24k belong to Asian and Middle Eastern markets, where gold is bought as a store of value first and an ornament second, which is why an Indian or Gulf piece is so often far higher karat than a western one of the same apparent style.

There is no international standard for what may be sold as gold. The United States sets the minimum at 10k. The United Kingdom permits 9k. Much of continental Europe allows 8k, marked 333, which cannot legally be called gold in either of the other two.

This matters when you inherit or import a piece. A German 333 chain is legitimately sold as gold in Germany and is a third pure; the same chain could not be described as gold in a US shop. It is still worth its gold content wherever you sell it, but do not assume a foreign stamp maps onto your local convention.

22k and 24k carry more gold per gram and are worth more, but they are soft, scratch easily and are rare in western jewellery. 14k dominates the US market precisely because it survives daily wear. When selling, karat determines the price per gram and nothing else. There is no premium for being harder or more common.

The one place the rule bends is at the very top. Recognised bullion, being 24k of known provenance, trades at 95 to 98% of spot rather than the 70 to 85% scrap range, because it needs no assay. That is a difference in form rather than in purity.