Rhodochrosite 370734 222457233 2008-06-29T12:55:40Z 92.82.46.130 the place for the firest descriptions of this mineral is incorrect {{Infobox mineral | name = Rhodochrosite | category = [[Mineral]] species | boxwidth = | boxbgcolor = | image = rhodesss.jpg | imagesize = 250 | caption = Rhodochrosite from [[Sweet Home Mine]], [[Alma, Colorado]], USA | formula = MnCO<sub>3</sub> | molweight = 114.95 g/mol | color = Red to pink, Brown to yellow, gray to white | habit = [[Massive]] to well [[crystaline]] | system = [[Trigonal]] - [[Hexagonal]] [[Scalenohedral]] | twinning = on the {0112} uncommon | cleavage = on the [1011] perfect | fracture = uneven, conchoidal | tenacity = brittle | mohs = 3.5-4 | luster = [[Vitreous]] | polish = | refractive = | opticalprop = Uniaxial (-) | birefringence = δ = 0.218 | dispersion = | pleochroism = weak | fluorescence= None | absorption = | streak = White | gravity = | density = 3.7 g/cm³ | melt = | fusibility = | diagnostic = | solubility = | diaphaneity = Transparent to translucent | other = | references = <ref>[http://www.mindat.org/min-3406.html Rhodochrosite: Rhodochrosite mineral information and data<!-- Bot generated title -->]</ref> <ref>[http://webmineral.com/data/Rhodochrosite.shtml Rhodochrosite Mineral Data<!-- Bot generated title -->]</ref> }} [[Image:Rhodochrosite Pink Form.jpg|250 px|thumb|right|Pink is the most common color of Rhodochrosite. Specimen mined near Silverton, [[Colorado]]]] '''Rhodochrosite''' is a [[manganese]] [[carbonate]] [[mineral]] with chemical composition [[Manganese(II) carbonate|MnCO<sub>3</sub>]]. In its (rare) pure form, it is typically a rose-red color, but impure specimens can be shades of pink to pale brown. The streak is white. Its [[Mohs hardness]] varies between 3.5 and 4. Its [[specific gravity]] is 3.5 to 3.7. It crystallizes in the trigonal system. The [[cleavage (crystal)|cleavage]] is typical rhombohedral carbonate cleavage in three directions. [[Crystal twinning]] often is present. It is transparent to translucent with [[Refractive index|refractive indices]] of ''nω''=1.814 to 1.816, ''nε''=1.596 to 1.598. It is often confused with the manganese silicate, [[rhodonite]], but is distinctly softer. Rhodochrosite forms a complete [[solid solution]] series with [[iron]] carbonate ([[siderite]]). [[Calcium]], (as well as [[magnesium]] and [[zinc]], to a limited extent) frequently substitutes for manganese in the structure, leading to lighter shades of red and pink, depending on the degree of substitution. It is for this reason that the most common color encountered is pink. Rhodochrosite occurs as a hydrothermal vein mineral along with other manganese minerals in low temperature ore deposits as in the silver mines of Romania where it was first found. Banded rhodochrosite is mined in Capillitas, [[Argentina]]. Catamarca, Argentina has an old inca silver mine that has produced fine stalatitic examples of rhodochrosite that are unique and very attractive. Cut cross-sections reveal concentric bands of light and dark rose colored layers. These specimens are carved and used for many ornamental purposes.<ref name="Galleries">{{cite web|url=http://www.galleries.com/minerals/carbonat/rhodochr/rhodochr.htm|title=Rhodochrosite (Manganese Carbonate)|publisher=Amethyst Galleries, Inc.|accessdate=2007-08-15}}</ref> Its main use is as an ore of [[manganese]] which is a key component of low-cost stainless steel formulations and certain alluminium alloys. Quality banded specimens are often used for decorative stones and [[jewelry]]. Due to its being relatively soft, and having perfect cleaveage, it is very difficult to cut, and therefore rarely found faceted in jewelry. It was first described in 1813 in reference to a sample from Cavnic, Maramureş, present-day [[Romania]]. According to Dimitrescu and Radulescu, 1966 and to Papp, 1997, this mineral was described for the first time in Sacaramb, Romania, not in Cavnic, Romania. The name is derived from the [[Greek (language)|Greek]] word for ''rose-colored''. [[Colorado]] officially named rhodochrosite as its state mineral in 2002 based on a proposal by a local high school (Platte Canyon High School in Bailey,Colorado). The reason for this lies in the fact that while the mineral is found worldwide, large red crystals are found only in a few places on earth, and some of the best specimens have been found in the Sweet Home Mine near [[Alma, Colorado]]. [[Image:Alma King rhodochrosite.jpg|right|250px|thumb|The ''Alma King'' is the largest known rhodochrosite crystal; it was found in the [[Sweet Home Mine]] near [[Alma, Colorado]]. It is on display in the [[Denver Museum of Nature and Science]].]] The [[Incas]] believed that rhodochrosite is the [[blood]] of their former rulers, turned to stone, therefore it is sometimes called "Rosa del Inca" or "Inca Rose".<ref name="GemRocks">{{cite web|url=http://www.cst.cmich.edu/users/dietr1rv/rhodochrosite.htm|title=GemRocks: Rhodochrosite|author=R.&nbsp;V. Dietrich|date=[[2005-07-16]]|accessdate=2007-08-15}}</ref><ref name="LGS">{{cite web|url=http://www.luckygemstones.com/rhodochrosite-jewelry-pink-love-gemstone.htm|title=Rhodochrosite Jewelry|publisher=''LuckyGemstones.com''|date=2007|accessdate=2007-08-15}}</ref> ==Rhodochrosite and silver mining== Manganese carbonate is extremely destructive to the amalgamation process used in the concentration of silver ores, and so until quality mineral specimens became highly sought after by collectors, they were often discarded on the mine dump. ==See also== [[Manganoan Calcite]] {{commonscat|Rhodochrosite}} ==Footnotes== {{reflist}} ==References== * Hurlbut, Cornelius S.; Klein, Cornelis, 1985, ''Manual of Mineralogy'', 20th ed., ISBN 0-471-80580-7 * [http://www.mindat.org/min-3406.html Mindat] * [http://webmineral.com/data/Rhodochrosite.shtml Webmineral data] * [http://mineral.galleries.com/minerals/carbonat/rhodochr/rhodochr.htm Mineral galleries] {{-}} {{Manganese minerals}} {{mineral-stub}} [[Category:Carbonate minerals]] [[Category:Manganese minerals]] [[Category:Symbols of Colorado]] [[de:Rhodochrosit]] [[es:Rodocrosita]] [[fr:Rhodochrosite]] [[gl:Rodocrosita]] [[he:רודוכרוזיט]] [[hu:Rodokrozit]] [[nl:Rhodochrosiet]] [[ja:菱マンガン鉱]] [[pl:Rodochrozyt]] [[pt:Rodocrosita]] [[ro:Rodocrozit]] [[ru:Родохрозит]] [[sk:Rodochrozit]] [[fi:Rodokrosiitti]]