Chrysoprase

Chrysoprase or 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'. Image File history File linksMetadata No higher resolution available. ... Image File history File linksMetadata No higher resolution available. ... A selection of gemstone pebbles made by tumbling rough rock with abrasive grit, in a rotating drum. ... Chalcedony knife, AD 1000-1200 Bloodstone redirects here. ... Quartz is one of the most common minerals in the Earths continental crust. ... General Name, Symbol, Number nickel, Ni, 28 Chemical series transition metals Group, Period, Block 10, 4, d Appearance lustrous, metallic and silvery with a gold tinge Atomic mass 58. ... Amethyst (SiO2) is a violet or purple variety of quartz often used as an ornament. ... Citrine Citrine, also called citrine quartz or citrine topaz, is an amber-colored gemstone. ... Agate is a term applied not to a distinct mineral species, but to an aggregate of various forms of silica, chiefly chalcedony. ... Imprint of a carnelian seal with Brahmi inscription Kusumadasasya (Flowers servant). 4-5th century CE, probably Punjab. ... Onyx is a banded variety of chalcedony, a cryptocrystalline form of quartz. ...

Due to its comparative scarcity and pleasing green color, chrysoprase is one of the most prized varieties of quartz. Higher quality specimens often rival fine jade, for which it is sometimes mistaken. Cut into cabochons (smooth domed gems with flat backs for use in jewelry), it can be as sought after as fine amethyst. A selection of antique, hand-crafted Chinese jade (jadeite) buttons Unworked Jade Jade is used as an ornamental stone, the term jade is applied to two different rocks that are made up of different silicate minerals. ... A cabochon or cabouchon is a gemstone which has been shaped and polished as opposed to facetted. ... Amethyst (SiO2) is a violet or purple variety of quartz often used as an ornament. ...

Unlike emerald which owes its beautiful green color to the presence of chromium, the color of chrysoprase is due to trace amounts of nickel in the structure. The nickel reportedly occurs as platelets of the talc-like mineral willemseite. Chrysoprase results from the deep weathering or lateritization of nickeliferous serpentinites or other ultramafic ophiolite rocks. In the Australian deposits, chrysoprase occurs as veins and nodules with brown goethite and other iron oxides in the magnesite-rich saprolite below an iron and silica cap. For other uses, see Emerald (disambiguation). ... General Name, Symbol, Number chromium, Cr, 24 Chemical series transition metals Group, Period, Block 6, 4, d Appearance silvery metallic Standard atomic weight 51. ... General Name, Symbol, Number nickel, Ni, 28 Chemical series transition metals Group, Period, Block 10, 4, d Appearance lustrous, metallic and silvery with a gold tinge Atomic mass 58. ... Cutting of laterite brickstones, Angadipuram, India Laterite is a surface formation in tropical areas which is enriched in iron and aluminium and develops by intensive and long lasting weathering of the underlying parent rock. ... A sample of serpentinite rock, partially made up of chrysotile Serpentinite is a rock comprised of one or more serpentine minerals. ... Ultramafic (or ultrabasic) rocks are igneous rocks with very low silica content (less than 45%), generally >18% MgO, high FeO, low potassium and are composed of usually greater than 90% mafic minerals (dark colored, high magnesium and iron content). ... Ophiolites are sections of oceanic lithosphere that have been uplifted or emplaced to be exposed within continental crustal rocks. ... Goethite, named after the German polymath Johann Wolfgang von Goethe, is an iron bearing oxide mineral found in soil and other low temperature environments. ... Iron oxide pigment There are a number of iron oxides: Iron oxides Iron(II) oxide or ferrous oxide (FeO) The black-coloured powder in particular can cause explosions as it readily ignites. ... Magnesite is magnesium carbonate, MgCO3. ... Saprolite is a soft, clay-rich, decomposed rock formed in place by chemical weathering of igneous or metamorphic rock. ...

As with all forms of quartz, chrysoprase has a hardness of 6 - 7 on the Mohs hardness scale and a conchoidal fracture like flint. Mohs scale of mineral hardness characterizes the scratch resistance of various minerals through the ability of a harder material to scratch a softer. ... A flint nodule from the Onondaga limestone layer, Buffalo, New York. ...

The best known sources of chrysoprase are Queensland, Western Australia, Germany, Poland, Russia, Arizona, California, and Brazil. Capital Brisbane Government Constitutional monarchy Governor Quentin Bryce Premier Peter Beattie (ALP) Federal representation  - House seats 28  - Senate seats 12 Gross State Product (2004-05)  - Product ($m)  $158,506 (3rd)  - Product per capita  $40,170/person (6th) Population (End of September 2006)  - Population  4,070,400 (3rd)  - Density  2. ... Capital Perth Government Constitutional monarchy Governor Ken Michael Premier Alan Carpenter (ALP) Federal representation  - House seats 15  - Senate seats 12 Gross State Product (2004-05)  - Product ($m)  $100,900 (4th)  - Product per capita  $50,355/person (3rd) Population (December 2006)  - Population  2,050,900 (4th)  - Density  0. ... Official language(s) English Capital Phoenix Largest city Phoenix Area  Ranked 6th  - Total 113,998 sq mi (295,254 km²)  - Width 310 miles (500 km)  - Length 400 miles (645 km)  - % water 0. ... Official language(s) English Capital Sacramento Largest city Los Angeles Area  Ranked 3rd  - Total 158,302 sq mi (410,000 km²)  - Width 250 miles (400 km)  - Length 770 miles (1,240 km)  - % water 4. ...

Popular Culture

Chrysoprase is the tenth precious stone, among 12 precious stones mentioned to make up the foundation stones of the city wall of the "New Jerusalem" as described in Revelation 21:20 (NLT).

References and external links

• Mindat.org
• Queensland government site