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| October 13, 2021

How To Test The Purity of A Gold Coin? - Muthoot Finance

Gold is a quintessential symbol of status, power, and wealth. People in India as well as across the world buy and invest in gold coins and bars as it is considered to be the safest investment option that provides good returns.

There are various ways that one can opt to buy gold coins. Some prefer going to the local jewellery stores while others go to the banks. Then there are NBFCs (Non Banking Financial Companies) that allow people to buy gold coins online. With so many options available, one needs to make sure that the gold they have invested in is pure.

This article discusses different ways to test if a gold coin is pure or fake without affecting the original shape and size.

  • The Stamp Test
    Whether you buy gold coins online or offline, always look for the BIS Hallmark stamp on it. The stamp tells you the purity of the gold coin in terms of karat or fineness. For instance, A BIS Hallmark on 1 gram gold coin in 24KT 999 purity means that it is 100% pure with no added metals. A hallmark typically includes,

    1. Valid purity in Karats - 8KT, 9KT, 10KT, 14KT, 18KT, 21KT, 22KT, and 24KT.
    2. Valid purity in fineness - 333, 375, 417, 583, 585, 625, 570, 833, 875, 916,958, and 999.

    By checking the hallmark on the gold coin, you will not only be aware of its authenticity and value but also ensure maximum future returns.

  • Letter Markings
    Another way of measuring the purity of gold coins is looking for the following letter markings on it, each having its own meaning.

    • GP - Gold Plating
    • GF - Gold Filled
    • GE - Gold Electroplated
    • HGP - High Gold Plating
    • HEG - Heavy Gold Electroplated

    These markings indicate that only a small percentage of gold was used to cover the coin made of any other metal and not gold.

  • The Skin Test

    This is one of the easiest and simplest ways to test if the gold coin is pure or fake. The process involves rubbing the gold coin against the skin for a couple of minutes and looking for a bluish or greenish tint on the area.

    If the coin is made of pure gold, the skin will remain unaffected. However, if the coin is made of any other metal, it will react with the skin and cause discolouration. This test can be performed easily at home in case you buy a gold coin online or at the store itself before purchase.

  • The Size And Weight

    Gold is denser than most metals and hence this test works pretty well, especially in the case of gold coins and bars.

    The process includes comparing the gold coin that you wish to test with the one for which you are sure about the purity. Also, you can use a set of callipers and a jeweller’s scale to check the size. If the gold coin appears different from the one that is real, authentic, this means it is a fake gold coin.

  • The Float Test

    Because of the density of Gold with 19.32 g/ml, it is heavier than other metals. So, if you wish to check the purity of a gold coin, simply put it in water. If it is made of pure gold, the coin will hover over the button or completely sink, whereas, in the case of any other metal, the coin will simply float.

    This is another quick and easy way to check if the gold coin is pure. However, it may be noted that the float test should not be the only criteria to check the purity as there can be other metals with higher density than gold.

  • The Magnet Test

    The magnet test is a perfect and convenient way to check the purity of gold coins as you can carry them around with you. The process includes holding a magnet against the coin and waiting for it to attract. In the case of pure gold, there will be no attraction, whereas, in the case of other metals, the coin will simply stick to the magnet.

    This quick test helps to instantly identify the purity of the gold, however, should not be the only criteria to make the final decision. Pair with other testing methods to ensure that the gold coin you are buying is pure and worth the price.

  • The Ceramic Test

    Another interesting way to instantly check if the gold coin is pure is to scratch it against an unglazed ceramic plate or a porcelain tile. In case both are not available, you can also use a black jewellery stone. On scratching, if the coin leaves a golden mark then it is pure and any other colour means that it is fake.

    Be cautious while performing the test as too harsh scratching can cause permanent damage to the product, thereby reducing its market value.

  • The Water Test

    As mentioned earlier, the standard density of 24kt gold is 19.32 g/ml and most of the other metals are not even near to this number in terms of density. Thus, making the water test a reliable way to test the purity of the gold coin. The process involves a few calculations explained below.

    Take the weight of the gold coin and put it into a bowl of water. Remember to measure the water levels before and after the coin was immersed. Now, calculate by subtracting the before measurement and the after measurement. Then divide the result with the weight of the coin to get the final outcome, which is the density. If this outcome matches the standard density of the gold then it is pure otherwise not.

  • The Acid Test

    This process involves testing the gold coin with acids such as vinegar or nitric acid. It simply requires you to put a few drops of any one of the mentioned acids on the gold coin and wait for its effect. In the case of pure gold, there will be no discolouration, whereas, in the case of other metals, the coin will turn blue, green or black.

    For further testing, you can rub the coin against the black jewellery stobe and then apply nitric acid on the mark. The acid will dissolve any other elements but gold, telling you if it is pure or fake.

  • The Magnifying Glass Test

    The magnifying glass test or the fail-safe test is one of the most effective ways to help you know the gold coin price with 999 purity. To perform this test, you need to hold the coin under a magnifying glass and look for any signs of discolourations or strange shine.

    As environmental properties do not affect the properties of gold, there are little to no chances that there will be any discolouration or corrosion. Besides, gold features an attractive soft yellow glow that is not extremely shiny. Any such signs on the gold coins mean that it is fake.

    It is important to check the purity of gold before buying to ensure maximum results, especially when bought as an investment. Besides, the safest option is to opt for trusted banks and other financial institutions like Muthoot Gold Bullion Corporation, part of The Muthoot Group that make it easy for you to buy pure and authentic gold coins online without any hassle.

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