Are you suspicious that a loose diamond or diamond jewellery that you bought is fake? If you have purchased a GIA-certified diamond, you can be rest assured that it is genuine. However, if the diamond was an inheritance or a gift, you have every right to be suspicious.

If you've got a diamond or a piece of diamond jewellery and you are in doubt about its genuineness, here are some tests that you can perform at home to discover the difference between authentic and fake diamonds.

Water Test:

Take a drinking glass and fill it with water. Drop the diamond carefully into it. If the gemstone floats at the surface of the water or underneath, it is a fake diamond. If the stone sinks, you have a real diamond on your hands. As diamonds have higher density than water, they get to the bottom of the glass.

Fog Test:

Hold the diamond between your fingers and blow a puff of air over it. You will see the formation of fog on it. If this fog dispels right away, the diamonds are real. Or, if it takes a few seconds for the fog to dispel, the stone is not the real one. Authentic diamonds conduct and disperse heat quickly.

Heat Test

Hold the diamond using a set of pliers and heat it for 30 seconds. Then, drop the stone into a glass filled with cold water. If the stone shatters, then it is not a real diamond. A real diamond is unresponsive to high heat.

UV Light Test:

Place the diamond under a UV light. If it emits blue-coloured glow, then the diamond is real. However, not all real diamonds glow and this doesn’t mean that it is a fake diamond. This test is not definitive and you can’t conclude depending on the colour emitted by the stone.

Sandpaper Test:

Rub the diamond physically with sandpaper. If the stone appears as if it is untouched, then it is a real diamond. On the other hand, if you notice any damage, then it is likely to be fake. Diamonds are the naturally-found hardest elements and will not get damaged if rubbed against any hard surface.

Weight Test:

If you have access to a cubic zirconia, you can compare their size and weight. Usually, a diamond weighs less than that of a cubic zirconia. If your diamond weighs 55% less than the weight of cubic zirconia, feel happy for having a real diamond.

Sunlight Test:

Diamonds reflect light in a unique pattern. If the inside of the stone sparkles white and gray while the outside reflects a rainbow of colours, then you have a real diamond. On the other hand, if the inside of the stone has rainbow colours, it’s probably a fake diamond.

Scratch Test:

This test involves simply scratching the diamond against a mirror. If the stone scratches the mirror, then you are having a real diamond.

Read-Through Test:

Place your diamond on a newspaper and try reading the text. If you are able to see through the stone and read the text, it is better to have the stone checked. Real diamonds refract lights in different directions, making it difficult to see through.

Microscope Test:

Place your diamond under a powerful microscope and evaluate its perfection. If the gemstone appears flawless, it is a fake diamond. Real diamonds are naturally formed elements and will have some external and internal flaws called inclusions.

Mounting Test:

If the mounted metal has engravings such as KT, PT or Plat, then it means that your gemstone is a real diamond. This is because real diamonds are often mounted on precious metals like gold, platinum or silver. However, if you see CZ, the stone is cubic zirconia which is not a real diamond.

While these tests appear to be easy to perform at home, it is always better to get an expert view. So, it is highly recommended to have it inspected by a professional jeweller who can spot a fake diamond accurately. Here at Diamond Story, we have diamond experts who have enough knowledge about the gemstones and can check your diamond for its authenticity using the state of the art devices. Simply bring in your diamond to us and have it evaluated for its authenticity. If you have any questions, call 03 9642 3649 and ask our diamond specialist now!  

Back to blog