Chrysoberyl Designs

The mineral or gemstone chrysoberyl, not to be confused with beryl, is an aluminate of beryllium with the formula BeAl2O4.  The name chrysoberyl is derived from the Greek words chrysos and beryllos, meaning "a gold-white spar". Despite the similarity of their names, chrysoberyl and beryl are two completely different gemstones. Chrysoberyl is the fourth-hardest natural gemstone and lies between corundum and topaz on the hardness scale. Chrysoberyl is a mineral consisting of ordinary colourless or yellow transparent chrysoberyl, cymophane (chrysoberyl cat's eye), and alexandrite.

An interesting feature of its crystals are the cyclic twins called trillings. These twinned crystals have a hexagonal appearance, but are the result of a triplet of twins with each "twin" taking up 120 degrees of the cyclic trilling.

There are three main varieties of chrysoberyl: ordinary yellow chrysoberyl, cat's eye or cymophane, and alexandrite. Although yellow chrysoberyl was referred to as chrysolite during the Victorian and Edwardian eras, that name is no longer used in the gemmological nomenclature.

Ordinary chrysoberyl is a yellowish-green, transparent to translucent chrysoberyl and has often been referred to in the literature as chrysolite due to the common olive colour of many of its gems, but that name is no longer used in the gemological nomenclature. When the mineral exhibits good pale green to yellow colour and is transparent, then it is used as a gemstone.

Alexandrite, a strongly pleochroic (trichroic) gem, will exhibit emerald green, red and orange-yellow colours and tend to change colour in artificial light compared to daylight. The colour change from red to green is due to strong absorption of light in the yellow and blue portions of the spectrum. Typically, alexandrite has an emerald-green colour in daylight but exhibit a raspberry-red colour in incandescent light.

Cymophane is popularly known as cat's eye. This variety exhibits pleasing chatoyant or opalescence that reminds one of an eye of a cat. When cut to produce a cabochon, the mineral forms a light-green specimen with a silky band of light extending across the surface of the stone.

Image	Description	Ct Weight	Price ($AUS)
	Private Collection Other Stones Available
	Private Collection Other Stones Available