- What are karats and how can they be used to determine the purity of gold?

Cyprus and many other countries of the world use a special system to evaluate, express and label metric gold purity. If gold has a purity of 999.9, it means that 1,000 grams of alloy contain 999.9 grams of gold and 0.1 gram of impurities.

Notably, 1,000 grams of gold with a purity of 850 contain 850 grams of pure gold and 150 grams of impurities (ligature), which harden the metal and/or change the color of the product.

The karat system is still widely used in the United States, South Africa, Britain and many other countries around the world. A purity of 24 karats means that out of 24 conventional pieces of alloy all 24 are gold. Purity of 18 karats means that out of 24 conventional pieces 18 pieces are gold and 6 pieces are impurities (ligature).

A simple formula can be used to convert the purity of gold. For example, in order to figure out the purity of 18-karat gold, you need to take the following features into account:

1. The maximum possible metric purity of gold, which is 1,000.
2. The maximum possible purity of gold in karats, which is equal to 24.
3. The actual purity of the product in karats, in this example it is 18. You need to divide the maximum possible metric purity of gold by the maximum possible purity of gold in karats and multiply the result by the purity of the product in karats: (1000/24​​) * 18 = 750.

To reverse the conversion process, you need to divide the metric purity of the product by the maximum possible metric purity and then multiply it by the maximum possible purity in karats: (750/1000) * 24 = 18 karats.

Instead of performing all these calculations, you can use a special online calculator. 

In our opinion, the metric system is better and offers greater accuracy. The karat system excludes fractions. For this reason, the karat system lends itself to a higher degree of accuracy. For example, 999 and 995 gold samples in the karat measurement system fall under the definition of 24-karat purity.