Gold is one of the most valuable and sought-after commodities on earth. Because of its value, cheaper jewellery can be made to look more expensive if it appears to contain gold, even if the gold is not genuine.
If you have a gold item, be it scrap or a valuable heirloom, you should know how to tell if the gold is genuine and how to avoid fakes. Here are some ways you can determine if the gold you have or are looking to buy is genuine.
A piece of gold jewellery is often engraved with a gold stamp that identifies its contents and/or maker. The gold stamps are usually displayed in a discreet place, such as on the inside of a ring or at the bottom of a gold bar.
The usual purity scales are based on carats and thousandths. The Hallmark test, also known as the magnifying glass test, is a good place to start to check if your gold is genuine.
Gold stamps can include:
- Valid purity numbers according to the carat table above.
- Valid purity numbers according to the thousandths system.
- False purity numbers (all other than the above)
- Manufacturer (such as ESPO for Esposito, etc.)
For example, if you see a gold stamp marked 16K, you can be sure that it is not real gold as that marking is not on the table above.
Gold hallmarks indicate the purity and manufacturer of the gold to give greater credibility to the authenticity of the jewellery and to make it easier to identify and verify. Since anyone can engrave any gold stamp, this test is not 100% error-free.
Another thing to look for is whether the markings indicate that the value has been measured in carats or thousandths. Any numbers other than the above indicate that the gold is fake.
Not all genuine gold jewellery has gold markings – for example, older jewellery may have had original markings that have been worn away.
Look for letter markings
Any gold marked less than 10K (41.7% purity) is considered fake.
Anyone familiar with the different quality levels will quickly recognise the following markings:
- GP – Gold Plated
- GF – Gold Filled
- GE – Gold Electroplated
- GEP – Gold-Electro Plated
- HGP – Heavily Gold Plated
- HEG – Heavy Gold Electroplated
You should avoid the above designations if you are looking for real gold. They indicate that the manufacturer has only coated the item with a thin layer of gold.
Remember the purity levels: 24k gold is 99.9% pure, while 18k gold is 75% pure. Completely 100% pure gold is unusual in that gold is very soft and would not be durable as jewellery. If someone tells you that they are selling jewellery made from 100% pure gold, you should be wary as it is extremely rare.
Test on your own skin
Hold a piece of gold jewellery between your hands for a few minutes. The sweat from your hands will either react with the metal and change the colour of your skin or not affect it at all. When real gold is in direct contact with your skin, there is no discolouration. If the gold is fake, it will cause your skin to turn black, blue or green where it comes into contact.
An exception occurs if you test gold on your skin while wearing make-up. When gold comes into contact with the make-up, your skin may turn black at the points of contact. Removing all make-up before the test makes the test more credible.
Alternatively, make-up can also be used to test the authenticity of the gold. Apply a liquid foundation and then powder over it. Once the make-up has dried, you can press the jewellery against your skin and drag it lightly over the skin where you have the make-up. If the jewellery leaves a black trace on your makeup, you probably have real gold.
Gold is extremely non-reactive, so real gold jewellery will never discolour your skin. However, using the make-up test is a unique way to also check if it is genuine.
If there is discolouration on gold jewellery, it means you have an alloy where there are other metals mixed in.
Compare the size and weight of the gold
Compare a piece of gold you want to test with one that is already known to be genuine.
Gold has a higher density than most other metals. If you use an accurate scale and find that the gold you have is too big for its weight or feels too light for its size, you probably have fake gold.
This test works best on coins and bars as you can easily find out the volume of the gold. This is one of the most reliable tests you can perform if you don’t have access to a gold testing machine.
Investment coins are actual coins made from precious metals, including gold, silver, palladium or platinum. They serve as collectors’ items, investments or as a hedge against inflation. Their dimensions are usually written on the front of the coin itself.
Hold a strong magnet to the gold and see if the gold moves. Gold is not magnetic, so there should be no attraction to magnets. If there is, you probably don’t have real gold.
But some of the base metals that can be mixed with gold are also non-magnetic, so you may get a false result. The test is not flawless, so it’s a good idea to do this in combination with another more accurate testing method.
Test the density of the gold
If you are holding a few grams of gold, it can be difficult to determine whether it is too light or heavy for its size. Sometimes non-metallic materials are used to counterfeit gold. Therefore, you can try putting the gold in water. If it is a metal, it will sink to the bottom of the container.
Scratch a ceramic or clinker tile with the gold
Take an unglazed ceramic plate or a piece of tile and scrape a piece of gold across its surface. Real gold will leave a golden mark or trail. Other metals will leave a black trace. This is one of the quickest ways to test if the gold is genuine, but people don’t always have access to ceramics or tiles. You can always visit Tavex to have your gold tested and valued!
Test with acids
Gold is a precious metal, which means it is resistant to oxidisation and acids. For this reason, you should wear eye, hand and clothing protection in case you spill during the test. To perform this test, you should rub your gold against a black stone to leave a visible mark. Then apply nitric acid to the mark. The acid will dissolve any base metals that are not real gold.
If the mark remains, apply nitric chloride acid, also called aqua regia (75% nitric acid and 25% hydrochloric acid), to the mark. This mixture dissolves gold, so if the mark disappears, the gold is genuine. We can see in the image above that two of the lines disappeared when covered with acid. In this case, it means that two of the lines were made with 18K gold.
Read more about how to test the purity of gold with acids here!
Test by using a gold expert
If you want to know for sure how pure your gold is, the most reliable way is to take it to a trusted jeweller and have it tested there.
Jewellers and gold experts have a variety of methods available to the public to authenticate gold. But those trying to sell minor precious metals as real gold have become increasingly sophisticated in their “craft”, so even the jeweller will probably use machine verification to be sure.
Most home analyses can give you an idea of whether your gold is genuine or not. While they are all good at showing probability, none of them are 100% conclusive.
The best way to be sure if your gold is genuine is to have an experienced and trusted jeweller evaluate it for you.