Rhodonite crystals in rock

A piece of rounded rhodonite

Rhodonite is a member of the pyroxene group of minerals, consisting of manganese inosilicate, (Mn,Fe,Mg,Ca)SiO₃, and crystallizing in the triclinic system. It commonly occurs as cleavable to compact masses with a rose-red color, often tending to brown because of surface oxidation. Image File history File links Size of this preview: 645 × 599 pixelsFull resolution (990 × 920 pixel, file size: 733 KB, MIME type: image/jpeg) Rodonita Source = the author is owner Date = created 2005 Author = Eurico Zimbres FGEL/UERJ Permission = Free for all use File historyClick on a date/time to... Image File history File links Size of this preview: 645 × 599 pixelsFull resolution (990 × 920 pixel, file size: 733 KB, MIME type: image/jpeg) Rodonita Source = the author is owner Date = created 2005 Author = Eurico Zimbres FGEL/UERJ Permission = Free for all use File historyClick on a date/time to... Image File history File links A piece of polished rhodonite (my photo) File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Image File history File links A piece of polished rhodonite (my photo) File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Figure 1:Mantle-peridotite xenolith with green peridot olivine and black pyroxene crystals from San Carlos Indian Reservation, Gila Co. ... A mineral is a naturally occurring substance formed through geological processes that has a characteristic chemical composition, a highly ordered atomic structure and specific physical properties. ... General Name, Symbol, Number manganese, Mn, 25 Chemical series transition metals Group, Period, Block 7, 4, d Appearance silvery metallic Standard atomic weight 54. ... The silicate minerals make up the largest and most important class of rock-forming minerals. ... In crystallography, the triclinic crystal system is one of the 7 lattice point groups. ... Illustration of a redox reaction Redox (shorthand for oxidation/reduction reaction) describes all chemical reactions in which atoms have their oxidation number (oxidation state) changed. ...

Rhodonite crystals often have a thick tabular habit, but are rare. It has a perfect, prismatic cleavage, almost at right angles. The hardness is 5.5 - 6.5, and the specific gravity 3.4 - 3.7; luster is vitreous, being less frequently pearly on cleavage surfaces. The manganese is often partly replaced by iron, magnesium, calcium, and sometimes zinc which may sometimes be present in considerable amounts; a greyish-brown variety containing as much as 20% of calcium oxide is called bustamite; fowlerite is a zinciferous variety containing 7% of zinc oxide. Quartz crystal Synthetic bismuth hopper crystal Insulin crystals Gallium, a metal that easily forms large single crystals A huge monocrystal of potassium dihydrogen phosphate grown from solution by Saint-Gobain for the megajoule laser of CEA. In chemistry and mineralogy, a crystal is a solid in which the constituent atoms... In mineralogy, shape and size give rise to descriptive terms applied to the typical appearance, or habit of crystals. ... Cleavage, in mineralogy, is the tendency of crystalline materials to split along definite planes, creating smooth surfaces, of which there are several named types: Basal cleavage: cleavage parallel to the base of a crystal, or to the plane of the lateral axes. ... Look up hardness in Wiktionary, the free dictionary. ... Relative density (also known as specific gravity) is a measure of the density of a material. ... For the file system called Lustre, see Lustre (file system) Lustre (American English: luster) is a description of the way light interacts with the surface of a crystal, rock or mineral. ... General Name, Symbol, Number manganese, Mn, 25 Chemical series transition metals Group, Period, Block 7, 4, d Appearance silvery metallic Standard atomic weight 54. ... General Name, symbol, number iron, Fe, 26 Chemical series transition metals Group, period, block 8, 4, d Appearance lustrous metallic with a grayish tinge Standard atomic weight 55. ... General Name, symbol, number magnesium, Mg, 12 Chemical series alkaline earth metals Group, period, block 2, 3, s Appearance silvery white solid at room temp Standard atomic weight 24. ... General Name, Symbol, Number calcium, Ca, 20 Chemical series alkaline earth metals Group, Period, Block 2, 4, s Appearance silvery white Standard atomic weight 40. ... General Name, Symbol, Number zinc, Zn, 30 Chemical series transition metals Group, Period, Block 12, 4, d Appearance bluish pale gray Standard atomic weight 65. ...

Rhodonite is a mineral liable to alteration, with the formation of manganese carbonate (rhodochrosite), hydrous silicates or oxides. The compact material, which is cut and polished for ornamental purposes, is often marked in a striking manner by veins and patches of these black alteration products. At Syedelnikova, near Ekaterinburg in the Urals, compact material of a good color occurs in a clay-slate and is extensively quarried: boulders of similar material found at Cummington, in Massachusetts ( cummingtonite ) have also been worked as an ornamental stone. In the iron and manganese mines at Pajsberg near Filipstadt and Langban in Vermland, Sweden, small brilliant and translucent crystals (pajsbergite) and cleavage masses occur. Fowlerite occurs as large, rough crystals, somewhat resembling pink feldspar, with franklinite and zinc ores in granular limestone at Franklin Furnace in New Jersey. Rhodochrosite from Sweet Home Mine, Alma, Colorado, USA Pink is the most common color of Rhodochrosite. ... Photograph of snow-covered Yekaterinburg Yekaterinburgs Church on the Blood, built on the spot where the Tsar and his family were murdered. ... This article is about the U.S. State. ... An ornamental stone is a stone used as a decoration. ... This article does not cite any references or sources. ... Spinel is one of a group of minerals which crystallize in the isometric system with an octahedral habit, and whose chemical compositions are analogous. ... -1... Franklin Furnace is a famous mineral location for rare zinc, iron, manganese minerals in old mines in Franklin, New Jersey USA. This locale produced more species of minerals (over 300) and more different fluorescent minerals than any other location. ... Official language(s) English de facto Capital Trenton Largest city Newark Area  Ranked 47th  - Total 8,729 sq mi (22,608 km²)  - Width 70 miles (110 km)  - Length 150 miles (240 km)  - % water 14. ...

The inosilicate (chain silicate) structure of rhodonite has a repeat unit of five silica tetrahedra. The rare polymorph pyroxmangite, formed at different conditions of pressure and temperature, has the same chemical composition but a repeat unit of seven tetrahedra. The silicate minerals make up the largest and most important class of rock-forming minerals. ...

Pink rhodonite contrasting with black manganese oxides is sometimes used as a gem material as seen in this specimen from Humboldt Co., Nevada, USA

Rhodonite is the official gem of Massachusetts [1]. Image File history File links Size of this preview: 518 × 599 pixelsFull resolution (538 × 622 pixel, file size: 102 KB, MIME type: image/jpeg) Source: Chris Ralph. ... Image File history File links Size of this preview: 518 × 599 pixelsFull resolution (538 × 622 pixel, file size: 102 KB, MIME type: image/jpeg) Source: Chris Ralph. ...

References

• This article incorporates text from the Encyclopædia Britannica Eleventh Edition, a publication now in the public domain.