How to Tell if Your Diamonds Are Real: Pt.2

Aug 7, 2018 | Alternative Investments, colored diamonds, Diamonds

Welcome to part 2 of our “How to Tell if Your Diamond is Real” series. In part 1, we saw how you can run some tests from the comfort of your home. While convenient, most of these test are not conclusive. If you want to be 100% certain for your diamond’s authenticity, the best thing you can do is seek the expertise of a seasoned gemologist.

gemologist looking at diamondSource

So what methods do the experts use to test for authenticity, and what can we learn from them?

The Use of a Loupe

The first thing any gemologist or diamond expert will do when evaluating a gem is to look at it through a Loupe. Loupes are special magnifying glasses specifically made for assessing diamonds, jewelry, and other kinds of gemstones.

These devices are used to locate small imperfections in a stones crystal lattice. While it might not look like it on the outside, most diamonds are not perfect and are not identical. Much like humans, they carry a unique fingerprint or pattern that sets them apart, and often times come with very slight internal imperfections. A gem that is 100% clear of all the above is usually not an authentic diamond.

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The Thermal Conductive Probe

The thermal conductivity probe or meter, also known as the “diamond tester” does exactly what its name implies; it tests the heat conductivity of a stone. If you remember from our previous article, diamonds are excellent heat conductors and will disperse heat rapidly after being warmed. If the heat is dispersed at a slower rate, then the diamond is not real.


While this might sound straightforward, it is actually not entirely conclusive. There are other, synthetic stones such as moissanite that might oftentimes have similar or identical conductivity to real diamonds. So further testing might be needed in order to distinguish these two types of gems, in the lab.

The Electric Conductivity Test

In addition to being excellent heat conductors, diamonds are also great at conducting electricity. This test is usually a follow-up to the thermal conductive probe test in order to distinguish between moissanite stones. Contrary to the above, moissanite gems are not as good as conducting electricity as they are with heat.

How to Test for Real vs Moissanite Diamonds

Technology has advanced so much in our times that the ability to create synthetic and affordable stones that are identical to real diamonds is now a reality. With more and more of these stones emerging, and bigger players starting to produce them (such as De Beers) it is only logical that we would want to determine if our stones are 100% authentic or synthetic. Again, these tests can only be carried out by certified gemologists in labs. So how do they do it?

Microscopic Examination

With the help of powerful microscopes that can magnify an image to 1200x, gemologists (and jewelers) are able to examine the gem in intense detail. This allows them to find any inclusions or minute characteristics found only in real diamonds.


Using X-Rays

Another test that can only be performed in specialized labs is the x-ray test. Here, the exposure will be able to tell gemologists if the stone has a radiolucent molecular structure (a trait found in real diamonds) or a radiopaque molecular structure (found in synthetics, cubic zirconium, etc.)

And that concludes part 2 of our series. Did you have any questions? Is there something we missed? Let us know!  And as always feel free to follow us on Twitter and LinkedIn.

To read more about the most famous colored diamonds in the world, see the link below:

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