Chrysolite - magmatic mineral, transparent garnet olivine

Chrysolite
The chemical formula: (Mg, Fe) 2 [SiO4].
Shingonia: rhombic.
The shape of the crystals is usually prismatic-dipyramidal. Well-formed crystals are very rare, usually chrysolite is represented by granular aggregates with irregular, isometric grains of 2-15 mm in size.
Color: golden green, sometimes with a yellow, herbal, olive, brown tint. Green coloration is caused by ferrous iron, and its brightness and intensity depend on the presence of nickel ions.
Hardness: 6,5-7, fragile; Viscosity and hardness vary in different directions.
Density: 3.0-3.5 g / cm3 (increases with increasing FeO content), chrysoberyl is characterized by low density.
Cleavage: imperfect.
Fracture: shell.
Glitter: glass.
Transparency: transparent.
The refraction is: ng = l, 669-1.975, nm = 1.651 - 1.865, np = 1.636-1.827.
Birefringence: 0.033-0.048.
Dispersion: 0.020.
Pleohroizm: weak.
Absorption: 497, 495, 493, 473, 453 nm (the brightest).

Chrysolite. 192.6 ct. One of the seven historical stones stored in the Diamond Fund, Moscow.
Chrysolite faceted. 10 carats. The Kugdinskoye field

Chrysolite is a magmatic mineral. Its name came from the Greek. Hriss - gold and lithos - stone. The synonym is olivine. Chrysolite is a transparent variety of olivine.

Chrysolites of bedrock deposits, in contrast to those found in placers, are intensely uniformly colored. However, in the same field, their coloration can be different. So, in the kimberlite pipe "Udachnaya" there are both light green and brown chrysolites. Used chrysolites in jewelry for a long time. On the field of olivine on one of the islands in the Red Sea, Pliny the Elder mentioned in the Natural History (23-79 AD).

Jewelry from chrysolite found during archaeological excavations in Alexandria. Known chisoliths of the period of the Greek ancient culture. Crusaders brought to Europe magnificent jewelry with chrysolite. Along with the emerald, it was in great demand at the beginning of this century. In modern jewelry production, chrysolite in the form of faceted inserts, more rarely cabochons, is used in gold products. The conventional form of its faceting is diamond, less often stepped.

Magnificent chrysolite is in the Diamond Fund. Its color is olive-green, the crystal is exceptionally clean, almost without defects (several thin cracks that do not reach the surface of the stone), the shape is elongated, the perimeter dimension is 5.2x3.5 cm, height 1.05 cm, weight 192.75 ct. A large, slightly convex platform is surrounded by stepped faces. The pavilion's facet consists of numerous irregular quadrangular faces.

In the CIS, chrysolite was mined in placers of the Ural rivers. It is found in the bedrock among the traps in Eastern Siberia, in diamondiferous kimberlite pipes of the Yakutsk diamondiferous province, in the clinohumite-serpophite-phlogopite-olivine veins of ultrabasic - alkaline intrusions (the Kugdinskoye deposit). According to the technical requirements for jewelery chrysolite in raw materials, the first class includes crystals or grains of green, yellowish and bright olive green color with dimensions of a defect-free area of ​​5x5x5 mm.

Defects of chrysolite: cloudiness, fissuring, inclusions of magnetite and golden brown mica, usually in areas with a yellowish tinge and dark (almost black) patches in the marginal parts of the grains of green chrysolite.

With chrysolite, there are prospects for expanding the application of one of the most beautiful green granite stones in the domestic jewelry business.

Popular gems, which are represented on the territory of the CIS (former USSR)