The purity of gold has always been one of the greatest concerns for gold jewellery buyers in India. In fact, in the past, qualms over the quality of gold available in India have forced many people to buy gold during their foreign trips. But with the advent of hallmarking in India, buyers are feeling more confident in buying gold. To ensure that as a buyer you are not cheated, you must know some of the gold basics. Let’s start with understanding the difference between Hallmarked Gold, KDM Gold and ‘916’ Gold.
Hallmarked Gold vs KDM Gold vs 916 Gold
When buying gold jewellery, you might have come across terms such as Hallmarked Gold, KDM Gold and 916 Gold and wondered what are they and what is the difference between them. Well, here is your answer.
What is Hallmark Gold?
A Hallmark in gold jewellery is a guarantee of purity and fineness of gold. It shows that the jewellery adheres to the international standards of purity. It safeguards the interests of buyers by helping them find if gold jewellery they are about to buy is fake or real. In India, the Bureau of Indian Standards (BIS) is authorised to assay the purity of gold. BIS-licensed Assaying and Hallmarking Centres grant hallmarks to BIS-certified gold jewellers.
The laser engraved Hallmark seal consists of 4 parts:
- BIS logo
- Retailer’s logo
- Purity in karat and fineness (916, 875, etc.)
- Assaying centre’s logo
What is KDM Gold?
Before getting into the details about KDM Gold, let us learn a bit about the making of gold jewellery. The beautiful and intricate gold jewellery designs that we admire are made through a process known as ‘Soldering’. It is a procedure of joining two metal pieces with the help of a filler metal known as ‘Solder’. At first the metal to be soldered, i.e., gold, is heated with a soldering iron and then the solder is melted into the connection. Since the melting point of solder is lower than that of gold, therefore, only the solder melts and not the parts that are being soldered
Solder is an alloy of gold and any other metal. Earlier, a combination of Gold and Copper, i.e., 60% gold and 40% copper, was used as Solder. For a very long time, it was used in crafting gold jewelleries as the alloy was strong and easy to prepare. But the drawback of the Solder was that its purity was only 60%. This implies that gold jewellery soldered with this alloy when melted will give you purity of less than 22 karat. This is the reason why your old jewelleries had 22/20 marking, where 22 karat represents the purity of gold used and 20 karat represents the melting purity.
To attain a high standard of purity in gold, Copper was replaced with Cadmium as it could be mixed in a ratio of 92% Gold and 8% Cadmium. The solder itself had the purity of 92%. In simpler words, it ensured the purity of gold jewellery remains constant irrespective of the amount of solder used. Such gold jewelleries, which were designed using Cadmium, started to be widely known as KDM Gold Jewelleries. But KDM gold posed serious health hazards on wearers and therefore is no longer in use.
Also Read : Know How Jewellers Quote Gold Jewellery Rates
What does ‘916 Gold’ mean?
If you checked for a BIS hallmark on a gold jewellery, then you must have noticed the ‘916’ number. You will find this number at all hallmarked gold jewelleries. The number is a part of the hallmark seal. But what does this number signify? The number ‘916’ signifies the finesse or purity of gold jewellery, i.e., 91.6 grams of pure 24 karat gold per 100 grams of alloy. The figure ‘916’ therefore denotes 22 karat by 24 karat of gold – (22 ÷ 24 = 916).
Why not make jewelleries in Pure Gold?
Pure gold is too soft to be made into wearable jewellery. There are a few 99% pure gold jewelleries but they are made with special alloys. Moreover, intricate designs are not feasible in pure gold.