Diamonds vs Moissanites - The Truth and the Lies
Sep 29, 2020
Diamonds vs Moissanites - The Truth and the Lies

Diamond simulants, primarily moissanite crystals, are increasingly being sold by companies seeking to take advantage of customer.
In light of the abundance of misconceptions about moissanite and other diamond simulants, we asked Sam, one of our top gemmologists at NOVITA DIAMONDS, to write a short but hopefully eye-opening article that will clarify all the misconceptions about moissanite and explain how they differ from real diamonds. You have the right as a customer to make informed decisions based on facts and not on marketing claims.


Our goal here is to explain the differences in straightforward terms so you can tell them apart easily.

The first difference is the way they look. Moissanites usually have a deeper tint than diamonds. Moissanites have an average colour of "J" if evaluated using the same colour grading system used for diamonds, where the scale goes from "D" to "Z". "J" stones are very brown in colour that is immediately apparent to the naked and untrained eye, and are not recommended for purchase.

Despite this, some companies were still offering moissanite of the "H" colour, based on their bold claims. Independent experts have not yet verified the existence of moissanite of the "H" colour. In my position as a gemmologist, I have inspected many moissanites, but have never encountered a moissanite of the "H" colour. As a result, most moissanites sellers attempt to make a quick profit by exploiting unwary consumers.

There is also a noticeable difference in sparkle colour between diamonds and moissanites, even to the naked eye. Moissanite's sparkles appear rainbow-like, while diamond's sparkles are pure white. Moissanites are all pleochroic, which means they show multiple colours when they are viewed from different angles – this is why diamonds and moissanites differ in sparkle colour. The double refractive properties of moissanite are what gives them their gawdy appearance; this is something that is only found in moissanite and never found in diamonds. Unlike moissanite, diamonds have optical properties that are consistent; their sparkles retain their colour no matter where they are viewed. You can easily tell the difference by examining moissanite from the top, paying attention to where the facets join- you'll find two joints instead of one.

The recent claim by companies that a new method of cutting moissanite prevents double fractions from forming is not surprising. As a result of double fraction being intrinsic to the material, no novel cutting method can bypass it from occurring, this claim should be regarded with extreme scepticism.


Moissanite sparkles look like rainbow colours. When comparing diamonds and moissanites one more thing stands out to the naked and untrained eye. It is the difference in the sparkles’ colours. While diamonds’ sparkles are white, moissanites produce iridescent colours. This significant difference in colours occur due to moissanites being pleochroic - showing two or three colours when viewed from different angles. 
The optical properties of diamonds are such that they don’t change the colour when being viewed from different angles. By contrast, all moissanites do have different colour appearances as they are double refractive. This part gets a bit more technical but don’t worry, we’ll stick to simple terms. This peculiarity is only found in moissanites and never in diamonds. To put it simply the easiest way for you to notice it is to examine a moissanite from its top taking a close look to where the facets join. You’ll notice that instead of seeing just one joint, you’ll spot two.

Nowadays some companies claim that they found a new way of cutting a moissanite which stops double fraction from happening. This information has yet been highly doubtful as double fraction does not come from the way a stone is cut but comes instead from the material it is made of.

Diamonds vs Moissanites - The Truth and the Lies


Moissanites will get a greenish tint. Bringing the stone close to direct fire for a few seconds will cause the stone to turn green.

Diamonds have faceted girdles. As diamonds are more expensive than moissanites, a lot more effort goes into cutting them. While moissanites have smooth girdles, diamonds are generally cut with facets even on the girdle.

Diamonds are harder than moissanites. There is a good reason for the saying “diamonds are forever”. The hardest material in nature is diamond, which scores a 10 out of 10. Moissanites, meanwhile, are the hardest simulants, including cubic zirconia and others. In spite of this, diamonds are still three times harder than moissanites, which can easily be scratched. Despite their intense hardness, diamonds are still more comfortable to wear than moissanites because moissanites are denser and heavier.


TRUE: Moissanites have a brown tint in colour on average, "J" when comparing it to a diamond colour grading system.
FALSE: Moissanites can be made white in colour (colourless).
TRUE: Moissanites sparkles are iridescent in colour, while diamonds' sparkles are white.
FALSE: Moissanites sparkle similarly or identical to diamonds.
TRUE: All moissanites suffer from double refraction, no matter how they are polished or cut.
FALSE: There is a way to cut moissanites to eliminate double fraction.
TRUE: Moissanites resemble costume jewellery due to the iridescent sparkles they produce.
FALSE: Moissanites are cut to the same standards as diamonds.
TRUE: Moissanites turn green when exposed to direct fire.

Note: As we explain in detail in our lab grown diamonds Hong Kong guide, the average moissanite tester in the market is incapable to truly test lab grown diamonds. Beware of dishonest jewellers pulling tricks on trusting customers. The scams are done by using a moissanite testers on lab grown diamonds HK rings to show a false reading as if the lab diamond HK was a moissanite.