Natural Diamond vs. Synthetic Moissanite

Synthetic Moissanite

Simulants are not lab-grown diamonds. Lab-grown diamonds are manufactured with essentially same chemical composition and crystal structure as natural diamonds. Simulants don't have any of diamond's physical or chemical properties, and the properties they do have vary widely. One of the diamond simulants in the market is synthetic moissanite. Here are some differences between natural diamond and synthetic moissanite. Knowing them can help you recognize a diamond that looks not quite right.  

Synthetic moissanite is silicon carbide with a natural counterpart that occurs as tiny grains in rocks and meteorites. It gets its name from Dr. Henri Moissan, a Nobel-Prize-winning chemist. Dr. Moissan discovered the natural mineral in 1893 while analyzing an ancient meteorite in Arizona. He noted its diamond-like qualities, but there was never enough of it to make commercial use possible.

Synthetic moissanite was first developed for industrial use. Because of its superior hardness—about 91 /4 on the Mohs scale—it served as an abrasive. It was introduced as a diamond simulant in the late 1990s. Although it tends to be slightly yellowish or greenish, synthetic moissanite is a convincing diamond simulant. It’s slightly less brilliant than diamond, and it has more fire than diamond and CZ, and less fire than synthetic rutile. This balance between brilliance and fire gives it an attractive appearance. Like CZ, synthetic moissanite is marketed as a jewel in its own right.

Some standard gemological tests can separate synthetic moissanite from diamond. For one thing, synthetic moissanite is doubly refractive while diamond is singly refractive. Under magnification, if you tilt it to the side and look through the bezel facets to the culet, you’ll see double images of the facet junctions, this is called doubling. You have to tilt it to see this because it’s usually cut so the doubling isn’t obvious through the table.

Unlike most other simulants, synthetic moissanite’s SG (3.21) is lower than diamond’s. That means it’s lighter, rather than heavier, than a diamond of the same size. Also, you won’t see bearding or naturals around the girdle of a faceted synthetic moissanite. These are fairly common in natural diamonds.

One feature of synthetic moissanite shocked the jewelry industry: It’s the first—and only—simulant that can actually fool some thermal testers. Its heat-conducting properties are so close to diamond’s that the thermal tester registers synthetic moissanite as “diamond” instead of “non-diamond.” To positively identify synthetic moissanite after it passes the diamond tester, examine the stone further for highly visible dispersion, and for doubling under 10X magnification. Also, several testing devices exist to identify synthetic moissanite based on its optical properties or its thermal and electrical conductivity.


Source: Gemological Institute of America 


We at Aya Gem don't use any diamond simulants in our jewelry. All the gemstones used in our creations are natural.

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