About Pure Gold
Gold is a natural metal. Gold jewelry is usually described in terms of caratage which is an indication of its gold content, for example 22 carat or 22K. Pure Gold is 24 carats (i.e. 99.9% pure). Such a metal in its purest state is very soft and impractical for making jewels.
To create jewelry that is practically wearable, gold has to be alloyed with other harder metals in the required proportions to make it malleable and durable. It is then called 22K, 18K and so on depending on the percentage of alloy that is added.
Gold jewelry used in India are of the following caratage:
22 kt Gold
21 kt Gold
18 kt Gold
Alloys are basically mixtures of more than one metal, usually added to increase the strength and enhance the colour of Gold. Copper and Silver are the commonly used metals in a Gold alloy.
The common Gold alloy to be used in any good quality gold jewel is 22 Kt Gold. It means that the gold is 91.6 % pure and hence the name 916 Pure Gold, an internationally accepted standard.
Hallmarking is a method of assessing the purity of gold by a competent authority. Hallmarking certifies that the jewelry conforms to National/International Standards of Purity.
In India, the BIS, i.e., Bureau of Indian Standards undertakes certification of purity of gold jewelry in accordance with Indian Standards IS:1417 Grades of Gold & Gold Alloys.
Every hallmarked jewel consists of the BIS logo, fineness number - caratage and mark of the BIS recognized assaying and hallmarking centre.