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An unusual specimen moissanite
In February 2018, the Gemological Institute of America (GIA) has published an article (author – Rebecca Tsang, staff gemologist GIA) about the unusual case simulating natural diamond submitted for examination to laboratory in carlsbad (USA).
The lab was presented the crystal, in appearance resembling a natural diamond. The stone had a light-green color, the shape close to octahedral, and the weight of 9.71 ct. Its size was of 11.79 x 11.61 x 9,69 mm.
In the preliminary studies, this sample was moissanite with its inherent physical (optical anisotropy, refractive index, specific gravity, conductivity, etc.), and Gemological properties.
During a more detailed study of the crystal shape with pseudooctahedral shape, showed signs of twinning. This explains the appearance similarity of shape of the test specimen with the octahedron.
On the surface double moissanite were numerous etching pits in the shape of a hexagon, and outputs the characteristic tubular tubules on the surface of the stone.
More in-depth studies with the use of spectral methods of research have confirmed the original conclusion about the mineral, as moissanite.
The conclusion about the artificial origin of this twinning splice was made on the basis of lack still finds crystals natural moissanite exceeding 5 mm and having the jewelry quality.
Authors:
- Rebecca Tsang, staff gemologist GIA
Source: GEMS&GEMOLOGY Winter 2017, Vol. 53, No. 4
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