Tips and Tricks for Testing Diamonds

One diamond tester on white

No matter how much (or how little) you spend on a diamond, you want to be sure it’s the genuine article. Whether the stone itself is set in a ring, a necklace, a pendant, or even loose, there are several tips and tricks you can use to assess its authenticity. This is an important thing to do. Diamonds hold such allure that not only are man-made replicas used in place of diamonds, but other natural gemstones such as white spinel may be used to create the look of a diamond jewelry but at a lower cost.

Here at Glendale Pawn and Jewelry, we have over 30 years’ experience within the jewelry industry – we understand how to check every diamond that comes through our doors; not just to ensure it’s genuine, but also to assess its condition, which helps us to give our customers the fairest price (according to the current industry costs).

To help you identify genuine diamonds from fakes, we’ve put together a list of tips!


Pay Attention to the Diamond’s Setting


If the diamond is set in a ring or other piece, it is unlikely that a diamond stone will be attached to cheap metal. You can check whether it’s real silver, platinum, or gold by the stamps inside the setting: 10K, 14K, and 18K are all good signs of its authenticity, as are 585, 750, 900, 950, PT, or Plat. A C.Z. stamp indicates that the stone is actually Cubic Zirconia, a synthetic diamond. Although, it is important that you keep in mind that faux gold is often stamped the same or similarly to real gold. So, this should not be your sole test for determining whether the diamond is real.


Breathe on the Stone


This is fairly simple: just take the stone, hold it close to your mouth, and breathe on it (as you would to fog a mirror, for example). A fake diamond will likely stay fogged for two or more seconds, whereas a genuine diamond takes the heat from your breath right away, refusing to fog as easily. Fake diamonds will also accumulate condensation if you breathe on them again and again – a real one stays clear no matter how much fogging you try! Be careful not to pass out as you try this.


Scope out those Flaws!


Jewelers use a loupe (that little scope you’ve probably seen in movies; we use them here in our store) to inspect diamonds. A vast majority of stones feature natural imperfections (known as ‘inclusions’), which can be spotted with your loupe – they may appear as subtle changes in color, or flecks. Fakes are typically created in clean locations rather than in the earth, which accounts for their generally flawless appearance.

However, real diamonds have been known to be without flaws, so be willing to perform other tests to make sure before you dismiss a stone as a fake! Throwing out a flawless diamond may be a costly mistake.


Take it to the News


We don’t mean you should report someone for trying to sell you a fake! Instead, this simple test involves trying to read the print in a newspaper through your stone (best used on loose diamonds): if you can read the text, or even see black shapes, this probably is a fake.

Real diamonds bend light passing through them, which means you will be unable to read through them – fake ones bend light less, and so are much clearer. In some cases, a diamond’s cut may well be disproportionate, so it’s best to combine this test with a few others just in case. If you don’t have a newspaper, you can even draw a straight line on a piece of paper.


Take the Stone for a Dip


Another useful method of testing for a real diamond is to drop the stone into a glass of water: if it sinks to the bottom, this is a good indicator of its authenticity; a non-diamond will float on the surface, or perhaps lower down (as far as the glass’s middle).


Let Things Get a Little Heated


Finally, another technique experts can use to check a diamond’s authenticity is the heat probe test. You see, as a diamond’s structure is so tight and even, heat will disperse through it very quickly, making it hard to heat up! The test usually takes around 30 seconds, and tests the length of time the stone retains the heat – a fake will be much easier to spot this way.


Here at Glendale Pawn and Jewelry, we always use more than one method to test a stone’s authenticity: this is usually a fast, effective process which lets us, and you, know how genuine a diamond actually is. Using a jeweler’s loupe, our trained staff can often immediately assess whether the stone in question is a diamond. In addition, we have several machines that specialize in testing stones to confirm that it is a natural stone. This ensures our customers can keep their trust in us – when we tell them a diamond is a diamond, they can believe it!