For millennia, people have purchased jewellery from jewellery stores. Gold jewellery may now be purchased online as well. However, it is critical to ensure that the jewellery is authentic. How can you tell if the gold you bought is pure or not? The Bureau of Indian Standards (BIS), a government agency, confirms the purity of gold purchased for this purpose. The procedure of confirming gold purity is known as hallmarking. The Bureau of Indian Standards (BIS) is the authorized authority to execute gold jewellery hallmarking, which is anticipated to promote transparency in the jewellery sector and customer trust.

Hallmarking

Hallmarks are official markings that are used in various nations to ensure the purity or fineness of precious metal goods. Currently, two precious metals, gold and silver, are subject to Hallmarking in India. On 14-, 18-, and 22-karat gold jewellery, hallmarking is permitted. In due future, further carats of gold, 20, 23, and 24, will be permitted for hallmarking.

The hallmarking programme has two primary goals, according to the BIS website:

1. a) To safeguard the public against adulteration
2. b) Requiring producers to adhere to legal fineness/purity criteria
3.  

To assure gold purity, four components must be present:

1. BIS Mark
2. Karat and fineness purity
3. Assaying and Hallmarking Centre identification mark/number
4. Jeweller's identification mark/number
5.  

1. BIS Mark

Any gold jewellery hallmarked by the BIS will display the BIS emblem, indicating that its purity has been tested in one of its certified laboratories.

2. Purity in Karat and fineness

Karat (denoted as KT) and fineness number are two ways to show gold purity. When measured in Karats, 24KT is the finest type of gold. However, 24K gold is thought to be too soft to be used in jewellery or ornaments. As a result, additional metals such as silver and zinc are mixed with gold in order to transform them into jewellery. The purity of a product is quantified in parts per thousand by its fineness number. As per the World Gold Council website, 24KT should be 1.0, i.e., 24/24, but gold is likely to have minor impurities and can only be refined to 999.9 parts per thousand. According to the BIS website, gold is only hallmarked for three categories of purity, namely, Karats. These are the following:

3. Assaying and hallmarking centre's mark/number

The laboratories where your gold jewellery is tested for purity is also obliged to display their emblem on the jewellery. Only BIS-licensed laboratories can assess the purity of gold. 

4. Jeweller's identification mark

The identification mark will also be placed by the jewellery store where you purchase your gold jewellery. This mark may be used by a BIS-certified jeweller or jewellery maker.