How to Tell Moissanite and Real Diamonds Apart

Even the Experts Can Be Fooled, Leaving Fraud a Real Possibility

Mar 18, 2009

Moissanite gemstone is so similar to diamonds that even expert jewelers and gemologists can't tell the two apart - leaving the market ripe for diamond forgeries and fraud

It used to be that if you were looking for a diamond-like gemstone that wouldn’t break the bank, the only options were glass chips, rhinestones, or cubic zirconia – none of them a perfect replica of a diamond. Today, the market for simulated diamonds has been overrun with the newly popular moissanite – a stone so similar to diamonds that it can be difficult for even experts to tell them apart. This is great for anyone who wants to buy a beautiful "diamond" engagement ring on a budget, but also opens the door for very convincing fakes to be sold as real diamonds.

What is Moissanite?

In its natural form, silicon carbide, it is a rare mineral found as an inclusion in diamonds, xenoliths, kimberlite and other rocks, but moissanite was first discovered in 1893 by scientists examining meteorite impact sites, who mistook the tiny crystals for diamonds.

Moissanite hit jewelry markets in the late 1990s, and is often found in bracelets, pendants, earrings, and even "diamond" engagement and wedding rings. All of the moissanite used in jewelry or for industrial purposes is synthesized in a laboratory.

What's the Catch? Telling Diamond and Moissanite Apart

It can be extremely difficult to tell moissanite apart from diamonds. Even jewelers and expert gemologists can be fooled. Traditional methods for identify fake diamonds don't work – even the technology can be misled by perfect moissanite.

Most jewelers identify diamonds based on their visual impression of the stone and a thermal conductivity test – but moissanite can pass these tests and easily be mistaken for real diamonds.

The only surefire way of identifying a stone as either diamond or moissanite is by comparing the refractive index. Moissanite has a higher refractive index and slightly lower weight than diamonds at the same carat level. It will also absorb UV light that diamonds will transmit.

Special technology, developed by Charles and Covard, the leading source for moissanite, tests the refractive index of a gemstone and can reliably identify moissanite where other machines cannot. The Tester Model 590 bombards a stone with UV light, which will be transmitted by a diamond but absorbed by moissanite. This test is designed to be used after a gemstone has passed the normal thermal conductivity test.

Moissanite, Jewelers, and the Potential for Diamond Fraud

Given the similarities between moissanite and diamonds, jewelers and consumers should be on the alert for fakes being passed off as the real thing. According to CBC News, hundreds of moissanites have been passed off as the real thing, and many jewelers are not as cautious as they should be in testing the "diamonds" that they purchase for resale.

Gemologist Martin Sheffield says, "I think that ultimately the consumer will get stung as well and the reason for this is that the jeweller will unknowingly sell a ring to a consumer thinking himself that it's a diamond ... and then when the consumer finds out 10 years later, it's too late."

The best thing to do, if you're in the market for a diamond, is to buy only on condition that it passes testing by a third-party expert appraiser. Whether diamond fraud is deliberate or accidental, it's certainly a possibility, so buyers should take care and do everything they can to protect themselves.

Sources

The copyright of the article How to Tell Moissanite and Real Diamonds Apart in Gemstones is owned by Victoria Anisman-Reiner. Permission to republish How to Tell Moissanite and Real Diamonds Apart in print or online must be granted by the author in writing.