How to Tell If a Diamond Is Natural or Lab Grown

Identifying man-made or synthetic diamonds

Natural diamond next to lab grown synthetic diamond
Can you tell which is natural?

How can I know if my diamond is real? This is a question we get all the time, and it’s not as simple as you might think. First, you have to decide what “real” means.

If you are not familiar with lab grown diamonds, you might want to check out our introduction to lab grown and synthetic diamonds before continuing with this article. So, now you know that lab grown diamonds are just as real as natural diamonds, but we still want to be able to tell them apart. When it comes to diamond simulants like Cubic Zirconia (CZ) or Moissanite, it is easy to identify them because they aren’t diamonds. But, with lab grown diamonds, the chemical structure and properties are all the same as natural diamond, so it becomes much more difficult to differentiate them.

Responsible Disclosure

The first thing to realize is that most lab grown diamonds are clearly and responsibly disclosed to be man-made. The big scare in the jewelry industry is non-disclosed lab grown diamonds that are sold as natural diamonds. But, it is important to know that the majority of lab grown diamond manufacturers are perfectly legitimate and honest organizations that are upfront about their products. Some even laser inscribe all of their diamonds to clearly mark them as lab grown.

The Type IIa Test

Lab grown synthetic diamond Type IIa tester with diamond
Our Type IIa diamond tester in action.

That said, we would still like to be able to tell if a diamond is natural or lab grown, whether it is disclosed or not. Fortunately, there are some tools available to help us do this. One of the best indicators of whether a diamond is lab grown is whether or not it is a Type IIa diamond. Type IIa is actually a gemological variant of the diamond that relates to how pure the carbon is that makes up the diamond. In nature, less than 2% of all diamonds are Type IIa, however, most gem quality lab grown diamonds are Type IIa. So, if a diamond is Type IIa, that’s a pretty good indication that it is lab grown.

However, like any gemological test, the Type IIa test is only an indicator for the gemologist to use. There are lab grown diamonds that are not Type IIa, and there are natural diamonds that are Type IIa, so it’s not a 100% conclusive test. Also, a diamond has to be completely loose (unmounted) to perform the test.

Photoluminescence Spectros­copy and UV Radiation

If you need to be absolutely, 100% sure whether a diamond is lab grown or natural, you can send it to specialized gem labs for testing. DeBeers and GIA (the Gemological Institute of America) have developed incredibly complex and sophisticated machines for answering this question. They have imaginative names like: DiamondCheck, DiamondSure, and DiamondView.

Roughly speaking, the machines work by bombarding a diamond with specific types of radiation (nothing harmful to humans) and analyzing what the stone outputs. There are certain, tell-tale signs of the various processes used to make lab grown diamonds that show up as spikes and troughs at specific wavelengths in the spectroscopic analysis. With CVD diamonds, the DiamondView machine can even enable a skilled gemologist to see microscopic growth lines where each layer of diamond material was built on the next. The end result is that we can ship a diamond to a GIA gem lab and get back a report telling us with certainty whether or not it is lab grown.

Is My Diamond Lab Grown?

So, should you be worried that your diamond is lab grown and no one told you? Probably not. The vast majority of gem quality synthetic diamonds being produced today are responsibly disclosed and sold as lab grown diamonds. Many major diamond suppliers have even purchased the diamond testing machines we just discussed to screen their inventories for undisclosed man-made diamonds. The jewelry industry as a whole has gone to tremendous lengths to ensure that when a diamond is sold as natural, it really is natural.

Plus, when you shop at Arden Jewelers, you have the added benefit of knowing that your diamond was checked by an experienced, GIA trained gemologist. We are one of the only shops in Sacramento with a full gem lab at our disposal including a Type IIa tester. So, you can buy with confidence knowing our experts have your back.

What people are saying

  1. J says:

    Awesome article well written!!!

What do you think?

We love feedback. If you have any questions, thoughts, or concerns about this page, please leave us a comment.
Don't worry. We won't publish your email address or spam you.