5 Ways to Tell Synthetic from Real Diamonds

February 27, 2020 - Jewelry & Luxury Items

In the precious & rare gemstone industry, there are con-artists out there that deal invaluable, rare commodities.

Some jewelers will try and get you to sell, buy, or take a pawn loan on a synthetic diamond under the guise of the real thing. This fraud is pretty uncommon, but it can still happen.

Your first line of defense is using PawnGuru to identify reputable pawnshops that are worth doing business with. On top of this, you should also get acquainted with ways to tell synthetic diamonds from real diamonds.

Identifying Real Diamonds Vs Synthetic Diamonds

When it comes to simulants like Cubic Zirconium or Moissanite, it’s easy to spot the differences. Simulants are completely different stones than a diamond. Simulants have distinguishing properties that inherently give it away from real diamonds. First off, they have different chemical properties and composition than both synthetic and natural diamonds. This means that they are subject to tests that will expose them as a simulant.

Synthetic diamonds are a little trickier to distinguish from a naturally made diamond. Synthetic diamonds are made in sophisticated laboratories and have no distinction in chemical makeup between a naturally occurring diamond. Yet because human-made diamonds have differing inclusions or flaws than mined diamonds there are still ways to tell. Specialized equipment will be used during a diamond appraisal. Be sure that your pawnshop or jewelry is certified by the Gemological Institute of America before doing business with them!

This article will cover tests to distinguish both synthetic diamonds and stimulants. This way, you’ll know when you have the rarest and valuable gemstone—a naturally mined diamond!

1. Responsible Disclosure & Certification

Many in the diamond industry are trepidatious about synthetic diamonds being sold as real diamonds. It’s a legitimate worry. Yet the fact is, the majority of laboratories making synthetic diamonds are honest, legitimate businesses. Most labs laser inscribe their diamonds. This way, there’s no doubt of the diamond’s origins. Alongside laser inscription, most mined diamonds are certified and will be accompanied by paperwork delineating the diamond’s grading and origin.

There is actually a strong market for synthetic diamonds so labeling is a non-issue. The controversy surrounding conflict diamonds lead many consumers to opt out buying naturally made diamonds. That and the price points for synthetic diamonds are up to 40% lower than natural diamonds. This pushes jewelers and pawnshops to be upfront about the diamonds in their showrooms.

2. The Type IIa Test

Think as the Type IIa Test as a constant variable to measure a diamond against. It works by comparing the concentration of carbon a Type IIa diamond will have against the diamond in question. Type IIa is actually a geological variant that indicates the purity of the carbon in a diamond’s chemical makeup. The test is conducted with a Type IIa diamond tester, a piece of equipment that most pawnshops that deal with diamonds will have on-site.

Less than 2% of naturally occurring, mined diamonds will register as a Type IIa diamond while most lab-grown diamonds are Type IIa. This results from laboratories simulating the factors of diamond growing—compressed carbon & heat—in a sterile, controlled environment. In nature, the environment is sporadic and leads to diamonds being increasingly less likely to register as Type IIa.

So, if you have a Type IIa diamond chances are it is most likely a synthetic diamond. However, there is a 2% chance that a lab diamond will not be Type IIa with the same chances of a mined diamond being a Type IIa. Therefore, this test is not 100% conclusive but can point you in the right direction with a wide margin of 98% accuracy.

3. Water Test

This is a simple way of identifying whether you have a diamond, simulant, or another precious gemstone. (However, if you are attempting to discern between a synthetic diamond and a natural diamond this test will not work!).

The water test is simple. Fill a glass 3/4 of the way full of water and drop the gemstone into the water. If the gemstone immediately sinks, you most likely have a diamond. If the gemstone slowly drops to the bottom or floats—you have a simulant. Diamonds have a high density which will make them sink immediately.

Since natural and lab-made diamonds have the same chemical properties, they will have the same density, and will both sink at the same rate. This means you can only rule out simulant gemstones, not a synthetic diamond with the water test.

4. The Heat Test

Since real diamonds are made from the strongest materials on the planet they are extremely durable and unresponsive to heat. The heat tests work by heating up the diamond with a torch or lighter for around 40 seconds. Do this with tongs and fireproof gloves.

Once you’ve heated the gemstone drop it in a glass of cold water. Since the gemstone will cool quickly, heat will contract while the stone expands. The cheaper material will crack while expanding at this rate while diamonds will remain unaffected.

Again, since synthetic diamonds have no chemical distinctions between natural diamonds this test will also not discern between the two. Only simulants can be ruled out with this test. Don’t worry! There is a 100% verifiable way that will empirically prove how to tell synthetic diamonds from real diamonds.

5. Photoluminescence Spectroscopy & UV Radiation

You will have to send your diamonds into a specialized gem lab for this test. Most jewelers and pawnshops won’t have this type of equipment but are usually more than happy to liaison the relationship between you and the lab.

Laboratories like the GIA have specialized machines that will bombard a diamond with specific types of radiation, then analyze the byproducts of the stone output. The process offers indicators of lab-grown diamonds. A lab-grown diamond will show spikes and troughs at specific wavelengths in the spectroscopic analysis. Also, microscopic growth lines where each layer of crystal structure grew in the CVD wafers will expose a lab-made diamond.

Use PawnGuru!

PawnGuru encourages you to visit a pawnshop with the necessary equipment and GIA certification to conduct diamond testing before testing your own jewelry. You might have a simulant that is still valuable! If you test the gemstones yourself, you could end up damaging or destroying the jewelry during the testing process.

David Stiebel
David Stiebel

David Stiebel is one of the cofounders of PawnGuru. David was educated at MIT, where he studied Math. He subsequently worked at Bain as a data scientist before starting PawnGuru in 2015. He started PawnGuru to build a better tool for pawn shops and consumers to connect.

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