Karat

Karat is a scale of 24. Pure gold is 24 karat, and every lower number says how many of those 24 parts are gold. Canada's Precious Metals Marking Regulations work the same way: the figure in a karat mark must equal the share of gold in the article multiplied by 24. So 14K is 14 parts gold and 10 parts other metals.

The other metals are alloys, and they do real work. Pure gold is soft, so alloying gives it durability, as the World Gold Council explains. GIA lists copper, silver and zinc as the alloying metals in yellow and rose gold, and nickel or palladium, copper and zinc in white gold. The karat tells you how much of the metal is gold. It does not tell you which alloy makes up the rest.

Divide the karat by 24. The regulations also allow purity to be stated in decimals, as a proportion of 1, which is why you see .417, .585 or .750 stamped on some pieces. This is called fineness, and it is the same information in thousandths. The World Gold Council lists .375 for 9 carat, .417 for 10, .583 (.585) for 14, .750 for 18 and .999 for 24. It notes that most manufacturers follow the European practice of making 14 carat gold slightly richer than 14/24, which is why 585 is the usual stamp.

The entries on 10K gold, 14K gold and 18K gold cover each karat in turn.

It depends on what the piece has to do. Higher karat means more gold, but a softer metal. 24K, being the purest, is also the softest and marks easily, and 14K and 18K suit everyday wear because they are alloyed for strength. Lower karats, such as 10K, hold more alloy.

Habits vary by region. A metallurgist's review of jewellery alloys by Dr Christopher Corti reports 22 carat in India and the sub-continent, 21 carat in the Gulf region, 18 carat as the predominant choice around the Mediterranean, 9 carat in the UK, and 10 and 14 carat in the USA. Treat that as a general picture, not a rule for any one buyer.

The World Gold Council also lists legal minimums, which differ by country: its page gives 10 carat for the US, and 9 carat for the UK, France, Austria, Portugal and Ireland (as of 2026; check current law before relying on it). Compare the karat of two pieces before you compare their prices, since a 14K chain and a 10K chain are not the same product. See gold vs platinum for the comparison with a different metal, and the entries on yellow gold, white gold and rose gold for colour.

The Precious Metals Marking Act says a quality mark that truly and correctly indicates the quality of the metal may be applied if the article meets the standards in the regulations. Under the regulations, a gold quality mark can be written in karats (“karat”, “carat”, “Kt.”, “Ct.”, “K” or “C”) or in decimals, with a minimum quality of 9 karats. The word “gold”, “or”, “G” or “Au” may accompany it.

The Competition Bureau, which enforces the Act, says marking is not mandatory, but a mark that is applied must be truthful and applied as the legislation prescribes, and it must be accompanied by a Canadian trademark unless the item was hallmarked under United Kingdom law or properly quality marked under another country's laws. The Bureau's page was last updated in March 2025, and the regulations were current to September 21, 2026.

There is a small allowed margin. Under section 13 of the regulations, the actual gold may fall short of the marked quality by no more than three parts per 1,000 where no solder is used, or seven parts per 1,000 where solder is used, with a wider allowance of 15 parts for white gold marked 18 karats or more where solder is used. For the full picture, see the entry on precious metal quality marks.

No, although they sound the same. Carat, with a C, is the unit of weight for diamonds and other gemstones: one metric carat is 200 milligrams. Karat is a measure of gold purity and has no connection to the weight of a stone. One ring can be 14K gold and set with a 1 carat diamond, and the two figures are independent. See carat weight.

It is easy to mix them up because Canada's regulations accept “carat” and “C” as ways of writing a gold quality mark. A gold ring stamped 14C would be 14 karat gold. If a number appears next to a diamond, it is a carat weight. If it appears next to the word gold or on the metal, it is a karat. For a piece in a particular karat, the custom jewellery design service can talk through the options.