Chrysoberyl
Chrysoberyl is really a treasure that is beautiful well suited to jewellery use. The combination of high hardness (8.5) and cleavage that is indistinct it extremely durable. Although its dispersion is low, it is an extremely bright and a gem that is colourful. Cat’s eye Chrysoberyl can be available. Other gems such as diopside and apatite may be called pet’s eyes, but Chrysoberyl ended up being the cat that is initial eye gem. It’s the cat that is finest’s eye of gems. The fibres that are silky so fine that the microscope will become necessary to see the average person fibres. This produces a very cat that is sharp eye effect.
Chrysoberyl is not perfectly understood in the gem world. It is notably overshadowed by certainly one of its more varieties that are famous Alexandrite. Alexandrite is the most widely known and many varieties that are valuable of. The quality of Alexandrite’s colour change effect is what accounts because of its value and desirability. It can change from shades of blue-green or green in daylight to shades of mauve, violet, purple or even red in incandescent light. Alexandrite normally available as a cat’s attention gem.
Occurrences of Chrysoberyl are widespread however, fine crystals are uncommon. Notable localities include: from numerous places in Brazil, with exceptional crystals from Tancredo, Itagua¸cu, and Colatina, Espirito Santo; from Faria Lemos, Santa Luzia de Carangola, and Americana, Teófilo Otoni, Minas Gerais; at Campo Formoso, Teixeira de Freitas, and Cachoeira, Bahia. From Maršíkov, Šumperk, Moravia, Czech Republic. At the Izumrudnye mines, Tokovaya River, near Yekaterinburg (Sverdlovsk), and Mursinka, Ural Mountains, Russia. From Miakanjovato, near Lake Alaotra, northeast of Ambatosoratra, Madagascar. Near Masvingo (Ft. Victoria), Zimbabwe. Abundant in gem gravel placers into the Ratnapura district, Sri Lanka. In the USA, from near Golden, Jefferson County, Colorado; in Maine, at Topsham, Sagadahoc County, from Paris, Norway, and Hartford, Oxford County, and elsewhere.
| Category: | Oxide minerals |
| Chemical Formula: | BeAl2O4 |
| Beryllium Aluminum Oxide | |
| Molecular Weight: | 126.97 gm |
| Composition: | Berylium | 7.10 % | Be | 19.70 % | BeO |
| Aluminum | 42.50 % | Al | 80.30 % | Al2O3 | |
| Oxygen | 50.40 % | O | |||
| 100.00 % | 100.00 % | = TOTAL OXIDE |
| Crystallography: | Orthorhombic – Dipyramidal |
| Crystal Habit: | Crystals are tabular on {001} or short prismatic along [100], to 22 cm; prominently striated on {001} || [100]. |
| Twinning: | Common on {130}, producing either flattened heart-shaped or pseudohexagonal multiple contacts and penetration twins. |
| Cleavage: | Distinct on {110}, imperfect on {010}, poor on {001}. |
| Fracture: | Irregular/Uneven to Conchoidal |
| Tenacity: | Brittle |
| Moh’s Hardness: | 8.5 |
| Density: | 3.75 (g/cm3) |
| Luminescence: | Weak red in SW and LW UV |
| Radioactivity: | Not Radioactive |
| Color: | Various shades of green, yellow, brownish to greenish black, may be raspberry-red under incandescent light when chromian; colourless, pale shades of yellow, green, or red in transmitted light |
