Synthetic Moissanite originally referred to a rare mineral discovered by Henri Moissan having a chemical formula SiC and various crystalline polymorphs. Earlier, this material had been synthesized in the laboratory and named silicon carbide (SiC).

Mineral moissanite was discovered by Henri Moissan while examining rock samples from a meteor crater located in Canyon Diablo, Arizona, in 1893. At first, he mistakenly identified the crystals as diamonds, but in 1904 he identified the crystals as silicon carbide. The mineral form of silicon carbide was named moissanite in honor of Moissan later on in his life.

Chemical Composition: 

Silicon Carbide - SiC

Classification / Type: 

This is a man made material. The term synthetic is used since it has a natural counterpart as inclusions seen in diamonds and other gemstones.

Colors / Varieties: 

All colors but colorless and light yellow are common.

Crystal System / Forms: 

Hexagonal

Hardness: 

9.5

Specific Gravity: 

3.22

Cleavage / Fracture: 

Indistinct / Conchoidal fracture

Optic Character: 

Anisotropic, D.R.; Uniaxial Positive

Lustre: 

Adamantine

Refractive Index / Birefringence: 

2.648 - 2.691 / 0.043

Pleochroism: 

Weak

Dispersion: 

0.105 (high fire)

Magnification: 

Strong doubling of facet edges, inclusions and culet (generally seen through kite facet), reflective needles.

U.V. Fluorescence: 

Inert

Spectrum: 

Not characteristic

Specific Tests: 

Moissanite probes are available which are defined for synthetic moissanite values of thermal conduction such as moissanite thermal probe.

Synthesis: 

Large crystals are grown by sublimation from a feed powder, diffusion through graphite and growth directly from the vapor phase on a seed crystal. In the sublimation process, the silicon carbide vaporizes and recrystallises without passing through the liquid stage.

Simulants (with separation tests): 

G.G.G. (dispersion, doubling, S.G.), Y.A.G. (dispersion, doubling, S.G.), Synthetic Cubic Zirconia (S.G., dispersion, doubling), Diamond (dispersion, doubling, inclusions, S.G.), Strontium Titanate (dispersion, doubling, S.G.), Sphene (dispersion, inclusions), Synthetic Rutile (S.G., dispersion), etc.

Geological Occurrence: 

In a laboratory.

Cuts & Uses: 

Facetted cuts.