Maybe you’re considering buying a diamond bracelet with a too-good-to-be-true price tag. Maybe you found a diamond ring while you were walking down the street. Or maybe you inherited your great grandmother’s jewelry. Whatever has brought you this stone, you wonder if your diamond is really a diamond. Have you lucked into the real thing, or are you dealing with a fake? There are quite a few tests you can use to check and see for yourself if your diamond is authentic.
Chances are you are familiar with the scratch test. This involves running a gem across glass to see if it scratches the surface. The problem with this test is that diamonds aren’t the only gemstone that can scratch glass. Furthermore, this basic test risks chipping or breaking your diamond. Unless you’re comfortable with the possibility of damaging a genuine diamond, don’t run this test.
A safe and easy way to check the stone is the fog test. For this test, exhale to fog the surface of the stone. If it stays fogged up for a couple of seconds, the gemstone is a fake. Genuine diamonds instantly disperse heat, so the fog will evaporate instantly. If you aren’t certain about whether the fog is disappearing quickly enough to tell whether or not the stone is authentic, take a stone that you know is either real or fake and fog the two stones at the same time. Compare how quickly the fog disappears.
Imperfections appear in virtually all diamonds. Mined diamonds usually have inclusions, which are natural blemishes. Inclusions are similar to a fingerprint or birthmark for a diamond, but false stones will not have them. Finding an imperfection is a good sign. Just keep in mind that flawless diamonds do exist. Even though an imperfection implies that a stone is probably a genuine diamond, stones that do not have imperfections aren’t automatically fakes.
If your gemstone is mounted in a ring, look at the inside of the band and check for a stamp. It is highly unlikely that real diamonds would be set in imitation gold, so if you find a stamp that indicates the band is real gold (10k, 14k, 18k, etc.), that’s a good sign. A “C.Z.” in the stamp stands for a common synthetic stone, Cubic Zirconia, which tells you definitively that the stone is an imposter.
If your stone is loose, you can try the newsprint test. Diamonds refract light in a certain way, which alters the appearance of print when you look through them. Place the stone crown down (point up) on newsprint. Real diamonds make the newsprint beneath it look like a smudge. If you can read the letters through the stone, it is not a diamond.
As explained by WP Diamonds, part of the White Pine Diamond Trading LLC, one of the world’s largest recycled diamonds company, “a small percentage of diamonds have fluorescence. This means that they glow when stimulated by long-wave Ultra Violet light. The majority exhibit blue fluorescence but sometimes diamonds may fluoresce pink, orange, green or red.” Because not all diamonds fluoresce under black light, this method cannot serve as a conclusive test of your stone’s validity.
Diamonds do not appear on x-rays. This is certainly not the most accessible test for most people, but if you somehow have access to an x-ray machine, this can be a simple way to determine the genuineness of the stone.
Whether you question the authenticity of a diamond you already own or are contemplating a purchase from the secondary market, there is only one way to be 100% sure that a diamond is real. Have the stone tested by a professional.
In the meantime, these do-it-yourself tests allow you to unofficially identify whether or not your diamond is the real thing.