Chrysoberyl

The name chrysoberyl is derived from the Greek words chrysos and beryllos means ' A gold white spar '. Chrysoberyl is the third hardest stone in the gem stone family. They are diamond (10), corundum(9), and chrysoberyl (8.5). The hardness of crysoberyl is 8.5 (Mohs scale hardness). Beryl and Chrysoberyl are not the same stone as they have a similarity of their name but both contain beryllium.

Chrysoberyl occurs in a range of colors from yellow, green, brown and its combination. Chrysoberyl usually prized for its mode of twinning. The crystal of crysoberyl habitually or attractive twins. The twins repeated cyclically to yeild six parts or six folds of twins called trilling.

In general  chrysoberyl is found in two variety. Cymophane is usually cut in cabachon to take advantage of its remarkable optical properties- cat's eye effect means a narrow line of light is visible in polished surface is due to needle like inclusion. The second variety of chysoberyl is alexandrite. Alexandrite is a rare variety of chrysoberyl. It is prized for its remarkable optical properties. In day light it looks bright green and in tungsten bulbs or candle light it looks red or brownish-red. So, therefore it looks emerald by day and ruby by night. The color change is due to chronic oxide, which in alexandrite partially replaces the aluminum oxide that occurs in the chemical composition of chrysoberyl.

It is very important in the gemstone industry cat's eye is referred to chrysoberyl although other minerals such as tourmaline, scapolite, corundum, spinel and quartz can form cat's eye effect.

DEPOSITS

The most important location in which Chrysoberyl is found include the Ural Mountains of Russia, Southern India, Sri-Lanka , Burma (Myanmar), Zimbabwe, Tanzania and Madagascar.

The most important source of alexandrite was the Ural mountains of Russia, where the variety was first described in 1830. Then in 1987, a new find was made at Hematita, Minas Gerais, Brazil. Alexandrite from Hematita has a nice color change from rasp berry red to bluish green. In 1993, there was another major find of alexandrite on the border of Tanzania and Mozambique.

PROPERTIES

INCLUSION

Inclusions are Feathers, Two Phase, Needles & Canals present in Chrysoberyl (Alexandrite). Inclusions found in Chrysoberyl cat's eye are Needles, Canals, short tubes parallel to the vertical axis of the crystal.

FAMOUS CHRYSOBERYL

The priceless cabochon Chrysoberyl cat's eye is a spectacular gemstone with huge weight of 465 carats. This Chrysoberyl cat's eye gemstone was discovered in the late 1800's in Pelmadulla paddy field, in Rathnapura district of Sri Lanka. It was originally owned by a family descended from King Rajasinghe the first, who ruled the island nation from 1581 to 1593. This magnificent cat's eye is found in the paddy fields owned by the Iddamalgoda Kumarihamy an aristocratic Chieftain in the Sabaragamuwa Province and Chief Custodian of Saman Devale, a 750 year old temple serving the region.

The Grand Lady Iddamalgoda Kumarihamy had four daughters, and gifted the uncut Cats-Eye to her eldest daughter's husband from another prominent family in the area. The stone was preserved in its rough form and in turn inherited by his son and the first Grandson of Iddamalgoda Kumarihamy.

SIMMULANT

Simulants of Chrysoberyl comes in a variety of form such as Needles, Canals, Short tubes parallel to the vertical axis of the crystal.