What is hallmarking?
BIS(Bureau of Indian standards), certifies the purity of the metal for gold and silver jewelleries sold in india. BIS evaluates if particular gold substance meets the standards of International Purity Standards. BIS hallmarked gold is available 995(24 carat), 916(22 carat),750(18 carat), 585(14 carat). Here hallmarked number “995” resembles the purity of gold which means 99.5 grams of pure gold in 100 grams of alloy.
According to BIS website, there are four components that one should look on the hallmarked gold jewellery to ensure the purity of gold which are as follows:
- BIS Mark
- Purity in Karat and fineness
- Assaying and Hallmarking Centre's identification mark/number;
- Jeweller's Identification mark/number
- Year of Making
According to the BIS website, it is the only agency in India approved by the government for hallmarking gold articles of any kind to ensure its purity. However, BIS hallmarking scheme is voluntary, not all jewellers offer hallmarked BIS jewellery. Some jewellers offer their in-house hallmarking of jeweller . So, before buying gold jewellery you must check with the jeweller whether they offer BIS hallmarking or not.
Purity in Karat and fineness
Purity of gold is indicated in two ways: Karat (denoted as KT) and fineness number. When purity of gold is measured in Karat, 24KT is considered the purest form of gold and considered too soft to be converted into any jewellery. Therefore, certain other metals such as silver and zinc are added to gold to convert it into jewellery.
Fineness number is measured in purity in parts per thousand. According to the World Gold Council website, 24KT should be 1.0, i.e., 24/24, but there is likely to be slight impurities in gold and can only be refined to a fineness level of 999.9 parts of thousand.
Assaying and hallmarking centre's mark/number:
Licensed laboratories of BIS are assessed to check the purity of gold and required to put their logo on the jewellery.
Jeweller's identification mark
The jewellery from where you are buying your gold jewellery will also put its identification mark. This mark can be of a BIS certified jeweller or jewellery manufacturer. BIS offers names of both gold and silver jewellers that are certified on their official website.
Year of making:
It was a code letter representing the year of hallmarking of jewellery which is decided by BIS. For example, Letter 'A 'was used for year 2000 and 'J for' year 2008.