Posted on July 6, 2015 by

Ask the Expert: How Can I Spot a Genuine Diamond?


Dear Diamond Expert,


There seem to be quite a few alternatives to diamonds that look just like the real thing! I’m so confused by all these lookalikes on the market and how they actually differ from diamonds. How can I spot a genuine diamond?

-Natalie T.




imitation diamonds set in studs

Ensure that what you have in your possession is the real thing with our trusted tips.


Dear Natalie T.,


What a great observation – we’re so glad you have brought this issue to our – and fellow diamond enthusiasts’ – attention! You are absolutely right when you point to the various diamond-like products available as an alternative to the real McCoy. Man-made diamonds and diamond simulants such as the widely known cubic zirconia (or CZ, as it’s referred to in the trade) and especially moissanite can appear so similar to genuine diamonds that they can fool even the most skilled gemologists. To distinguish between a lookalike and a real diamond, there are several ways to determine from the comfort of your own home whether the sparkling bauble you have in your hand is indeed an authentic diamond.


The most practical means of finding out whether your diamond-like substance is a diamond is to view the object using a loupe, a small magnifying glass used to look closely at the internal (and external) details of a gemstone, typically at ten times the magnification. Because natural diamonds are borne of the earth, flaws are to be expected. When you loupe a gemstone and see that everything inside looks too clean and perfect, chances are it’s an imitation. On the other hand, man-made, also known as lab-grown, diamonds can be flawless, so if you have any real doubts, consult a gemologist instead of casting it aside. Another thing you can do is look at the edges of the gem. Real diamonds have sharp edges while the edges of a counterfeit are usually rounded.


While viewing your gem under a loupe, you should also inspect the gemstone’s mounting and engraved hallmarks that indicate the type of metal the mounting is made of – metals that are merely gold-plated or silver will normally not house a diamond because precious gemstones are generally paired with precious metals. You can therefore expect a diamond to be set in some type of gold or platinum. Standard numeric stamps to look for on a precious metal mounting are: 950 (platinum); 999 (24K gold); 916 (22K gold); 750 (18K gold); 585 (14K gold); 417 (10K gold). Stay away from anything with 925 (sterling silver) as these mountings do not usually contain precious gems like diamonds.


Another method is to check the refractivity of your gemstone. Diamonds are highly refractive, which means that light entering them is sharply bent. If your gem is unmounted, place it on top of a piece of paper that contains any text. If you can clearly make out the letters or numbers through the gemstone, it’s highly likely that you do not have a real diamond. If your gem is mounted and the mounting is at all visible through the gem, again that probably means it’s not a genuine diamond.


Above all else, the guaranteed way to tell whether a gemstone is a real diamond is to take it to a trained gemologist who has experience working with diamonds. He or she will be able to tell you definitively whether you have a real diamond on your hands so that you’re not left wondering anymore. Bear in mind that you will need to pay for such a service.


Now, Natalie T., I know you’re asking, “Well, what are these other diamond-like gems I see out there that look so much like real diamonds?” There are a few in particular that seem to be prevalent right now.


Man-made/lab-grown diamonds: Man-made, or lab-grown, diamonds are actually real diamonds because they have the same chemical and physical makeup as natural (mined) diamonds. These diamonds are grown in the lab – a controlled environment – and are the product of a system that mimics the natural process. Man-made diamonds are identical to natural diamonds down to the very last atom and look exactly the same as mined diamonds. They generally cost 20 to 30 percent cheaper than mined diamonds.


Cubic zirconia (CZ): Unlike man-made/lab-grown diamonds, cubic zirconia (CZ) are not diamond, but diamond simulants. They do not possess the same chemical composition as diamonds. CZ is the crystalline form of zirconium dioxide (ZrO2). Unlike diamonds, CZ tend to be scratched easily and, most important for diamond devotees, lack the brilliance and fire of diamonds.


Moissanite: A diamond simulant, moissanite is another synthetic gemstone that completely dazzles the eyes. Moissanites are harder than CZ and possess a fire that is more stunning – albeit man-made – than a natural mined diamond’s.



Have a burning question that you’d like the Diamond Expert to address? Send us your diamond-related questions today! You can ask your question directly in the comments section below or send an e-mail to! Keep your eyes peeled for upcoming “Ask the Expert” segments – your question just might be answered by the Diamond Expert!

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