Chrysoprase from Kazakhstan

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Chrysoprase (Chrysophrase)

en.wikipedia.org
Chrysoprase (also chrysophrase) is a gemstone variety of chalcedony (fibrous form of quartz) that contains small quantities
of nickel. Its color is normally apple-green, but varies to deep green. It is cryptocrystalline, which means that it is composed
of crystals so fine that they cannot be seen as distinct particles under normal magnification. This sets it apart from rock
crystal, amethyst, citrine, and the other varieties of crystalline quartz which are basically transparent and formed from easily
recognized six-sided crystals. Other members of the cryptocrystalline quartz family include agate, carnelian, and onyx. Unlike
many non-transparent members of the quartz family, it is the color of chrysoprase, rather than any pattern of markings, that
makes it desirable. The word chrysoprase comes from the Greek chrysos meaning 'gold' and prason, meaning 'leek'.

www.galleries.com
Chrysoprase (also chrysophrase) is a gemstone variety of chalcedony (fibrous form of quartz) that contains small quantities of nickel. Its color is
normally apple-green, but varies to deep green. It is cryptocrystalline, which means that it is composed of crystals so fine that they cannot be
seen as distinct particles under normal magnification. This sets it apart from rock crystal, amethyst, citrine, and the other varieties of crystalline
quartz which are basically transparent and formed from easily recognized six-sided crystals. Other members of the cryptocrystalline quartz
family include agate, carnelian, and onyx. Unlike many non-transparent members of the quartz family, it is the color of chrysoprase, rather than
any pattern of markings, that makes it desirable. The word chrysoprase comes from the Greek chrysos meaning 'gold' and prason, meaning
'leek'....

www.nrm.qld.gov.au
Gem quality chrysoprase
The identifying properties of gem quality chrysoprase are:

Colour: pale green, yellowish green, apple green, deep green
Diaphaneity: translucent to opaque
Lustre: vitreous to resinous
Hardness (Mohs scale): 6–7
Specific gravity: 2.58–2.64
Refractive index: 1.53-1.54
Birefringence: form birefringence 0.004
Chelsea filter reaction: green
Ultra-violet fluorescence: none

Production
Chrysoprase of high quality has been produced commercially since the early 1960s from the Marlborough district of Central Queensland, 90 km
north-west of Rockhampton. The main mine at Marlborough is owned and operated by Gumigil Pty Ltd, a Hong Kong-based company. Its entire
production is sent to Hong Kong for processing and sale.

A second smaller mine, previously operated by Kajar Pty Ltd is now owned by Viper Resources Pty Ltd, a subsidiary of Cobra Resources NL.

Though considerable quantities of chrysoprase have been produced from this mine in past years, it has been inactive for some time. However,
the present owners have undertaken a program of testing and drilling to assess the deposit, and production is likely to resume shortly.

In South Australia, material mainly of carving grade has been won from the Mount Davies (Pipalyatjara) deposits. Most of this material has
probably been directed to the US and Korean markets....

www.bernardine.com
Chrysoprase was used by the Greeks, Romans, and the Egyptians in jewelry and other ornamental objects and because of its semi-opaque
green color, it is often mistaken for Imperial jadeite. One of the most valuable chalcedony gem stones, chrysoprase is prized for its color and
rarity, it is a 7 on the Mohs scale of hardness.