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'. A selection of gemstone pebbles made by tumbling rough rock with abrasive grit, in a rotating drum. ... Chalcedony Knife, AD 1000-1200 Chalcedony is one of the cryptocrystalline varieties of the mineral quartz, having a waxy luster. ... Quartz is amongst 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 Atomic mass 58. ... Amethyst (SiO2) is a violet or purple variety of quartz often used as an ornament. ... ... 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 vases 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 jadeite jade buttons Jade An ornamental stone, jade is a name applied to two 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. Emerald (Be3Al2SiO6) is a variety of the mineral beryl, colored green by trace amounts of chromium and sometimes iron. ... General Name, Symbol, Number chromium, Cr, 24 Chemical series transition metals Group, Period, Block 6, 4, d Appearance silvery metallic Atomic mass 51. ... General Name, Symbol, Number nickel, Ni, 28 Chemical series transition metals Group, Period, Block 10, 4, d Appearance lustrous, metallic Atomic mass 58. ... Laterite is a red-colored clay rich soil found in the tropics and subtropics. ... Serpentinite is a rock comprised of an admixture of 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 is a iron bearing oxide mineral found in soil and other low temperature enviroments. ... 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. ... Pebble beach made up of flint nodules eroded out of the nearby chalk cliffs, Cape Arkona, Rügen Flint (or flintstone) is a hard, sedimentary cryptocrystalline silica rock with a glassy appearance. ...

The best known sources of chrysoprase are Queensland, Western Australia, Germany, Poland, Russia, Arizona, California, and Brazil. Emblems: ? (please edit) Motto: Audax at Fidelis (Bold but Faithful) Slogan or Nickname: Sunshine State/Smart State Other Australian states and territories Capital Brisbane Government Governor Premier Const. ... Motto: Cygnis Insignis (Distinguished by its swans) Nickname: Wildflower State Other Australian states and territories Capital Perth Government Governor Premier Const. ... Official language(s) None Capital Phoenix Largest city Phoenix Area  - Total   - Width   - Length    - % water  - Latitude  - Longitude Ranked 6th 113,998 sq mi  295,254 km² 310 miles  500 km 400 miles  645 km 0. ... Official language(s) English Capital Sacramento Largest city Los Angeles Area  - Total   - Width   - Length    - % water  - Latitude  - Longitude Ranked 3rd 158,302 sq mi  410,000 km² 250 miles  402. ...

References and external links

• Mindat.org
• Queensland government site