What Is 21K Gold?
21K is the karat most jewellery in the UAE and the Gulf is made from. Here is what the number actually means.
What does the number 21 mean?
Karat measures the share of pure gold out of 24 parts. 21K means 21 parts gold and 3 parts other metals — that is 87.5% gold, written on the hallmark as 875.
The added metals (usually silver and copper) are not an adulteration; pure gold is very soft and is not suited on its own to a piece worn every day.
Why is it the most common in the Gulf?
Because it balances a high gold content and a clear yellow colour on one side with enough hardness for fine openwork and engraving on the other. 22K is yellower but softer, and 18K is harder but less yellow.
How do I check the karat?
By the hallmark. Federal Law No. 11 of 2015 requires every piece to carry the type of metal, the purity number and the mark of the hallmarking authority. Ask to see the hallmark under a loupe, and look for the number 875.
Quick questions
How much gold is in 21K?
87.5% pure gold, or 875 parts in every thousand — the number stamped on the piece.
Does 21K gold rust or change colour?
No. Gold does not rust or oxidise; what dulls is surface dirt, and it comes off with cleaning.