Karat & Carat
It is likely that many of us have come across the term 'Karat' and ‘Carat’ in relation to gold and gemstones. Fineness is another way of expressing the precious metal content of gold jewellery, and represents the purity in parts per thousand. When stamped on jewellery, usually this is stated without the decimal point.
A karat is a measurement indicating the proportion of gold in an alloy out of 24 parts, so 18K gold is 18/24 parts gold.
A carat is a unit of weight used to measure the size of a precious gemstone such as a diamond. However, the use of carat (in place of karat) to indicate the fineness of gold is also considered acceptable. You may see it abbreviated to these symbols: ct, K or kt.
24 Karat or 24k is the ultimate gold Karat. It's the purest form and consists of 99.9% gold. It is naturally yellow and highly valuable, but very soft and malleable. In India, the 24 karat gold known as Kundan is used for making Jadau (pronounced as jaraaoo) jewellery. The thin sheet of Kundan (pure gold) is used to cover the stones that are embedded in Lac (wax). Therefore, no clasps or prongs are needed to set the jewellery.
24 Karat Jewellery should be stamped as 1.0 (24/24 = 1.00). However, in practice, there is likely to be a very slight impurity in any gold, and it can only be refined to a fineness level of 999.9 parts per thousand. This is stated as 999.9.
22 Karat or 22k consists of around 91.6% gold and so is highly shiny and yellow. It is also very soft, so it's more suitable for plain gold jewellery, such as wedding bands or carved jewels.
22K jewellery is stamped as 916.
18 Karat or 18k contains 75% gold and 25% of durable metal alloys. White metals are be added to create white gold, while copper is added to create rose gold.
18K jewellery is stamped as 750
14 Karat or 14k has about 58.5% pure gold, and showcases a warm yellow hue.
14K jewellery is stamped as 585
10 Karat or 10k contains about 41.7% gold, 52% silver and 6.3% copper.
9 Karat or 9k has 37.5% pure gold ,and portrays a light yellow hue.