While buying gold ornaments or jewellery you must have noticed the seller or representative often describing the unit in Karat.
Karat is a unit of measure to know the purity of gold. If the seller tells you a particular jewellery of 22 karat then it means, that jewellery has 91.06% (22/24) of gold and balance 8.4% of metals like silver, zinc etc.
Gold is very soft to make jewellery, for this reason seller use to mix silver, copper or zinc to it.
You should not get confused between carat and karat. Both are used to measure purity but “carat” is specifically used to measure purity of precious stones and “Karat” is used to measure purity of Gold.
Gold jeweleries are measured in different Karat and based on that, price has been calculated. Karat is calculated as 24 times of the gold mass divided by the total mass.
24 karat is fine and pure having 99.99% gold mass in it and balances other metals. Similarly in 22 karat you have 22/24 part of pure gold and balance of other metals.
| Karat | Gold in % | Other Metal in % |
| 24k | 99.99% | 0.01% |
| 22k | 91.6% (22/24) | 8.4% (2/24) |
| 18k | 75% (18/24) | 24% (6/24) |
| 14k | 58.5% (14/24) | 41.5% (10/24) |
| 10k | 41.7% (10/24) | 58.3% (14/24) |
| 6k | 25% (6/24) | 75% (18/24) |
For example, if you have any gold jewellery of 22k then after melting it you will get 91.6% of pure gold and balance will be other materials mixed to it. While exchanging at a jewellery shop the buyer will also pay you the value of 91.6%. In India, you will find most jewellery with 22k i.e. 91.6% of gold in it.
All most all jewellery will have a mark in it to let you know the purity of gold used in it. If you did not find it then ask the seller to show you. You can also test jewellery to identify if it’s made up of pure gold.
How to test purity of Gold
You can test purity of gold with the help of nitric acid test. You can ask your jeweler to test it on your behalf as nitric acid is very difficult to get from market. To do this test you need to keep your jewellery in a stainless steel container and then take few drops of nitric acid and put it on the jewellery. If it is made up of pure gold then you will not see any reaction otherwise the jewellery will turn green or milk-colored if it’s gold plated.
You can also request the jewelers to carry on electronic test for you. This device will test gold’s electrical conductivity to let you know if it’s actual gold and will also let you know its purity.
