Synthetic moissanite
Synthetic Moissanite | |
---|---|
Chemical composition | Silicon Carbide - SiC |
Crystal system | Hexagonal |
Habit | Boule plates |
Cleavage | Weak (good parting) |
Fracture | Unknown |
Hardness | 9.25 |
Optic nature | Uniaxial + |
Refractive index | 2.648 - 2.691 |
Birefringence | 0.043 |
Dispersion | High, 0.104 |
Specific gravity | 3.22 |
Lustre | Sub-adamantine |
Pleochroism | Unknown |
Moissanite is a natural occurring mineral that is named after its discoverer, 1906 Nobel Prize (chemistry) winner Henri Moissan (1852-1907). As a natural source, this mineral is not suitable to be cut into gemstones as it occurs in too small grains.
Synthesizing moissanite has never been a real problem, however at first it was only synthesized for industrial purposes. This material, with a hardness of 9.25 on Moh's scale, is known by many bench jewelers and lapidarists as "carborundum" and is widely used as a sharpening tool for gravers and scrapers. As many who use carborundum can testify, this material is not very attractive as a gemstone.
Around 1987 Cree Research found a method to produce gemstone quality synthetic moissanite, but it was not until 1993 that a near-colorless crystal was obtained. Today this gemstone synthetic is marketed as Charles & Colvard created Moissanite™.
Although a nice synthetic on its own, this material is used mainly as a diamond simulant. Since the arrival of synthetic cubic zirconia in 1976, this is the most convincing diamond simulant, although a trained eye can easily separate synthetic moissanite from diamond.
References
- Synthetic moissanite: A new man-made jewel - Kurt Nassau, Current Science Vol 79 No 11, 10th Dec 2000 (Indian Academy of Science).