Moganite
Moganite | |
---|---|
General | |
Category | Tectosilicate, quartz group |
Formula (repeating unit) | SiO2 |
Strunz classification | 4.DA.20 |
Dana classification | 75.01.04.02 |
Crystal system | Monoclinic |
Crystal class | Prismatic (2/m) (same H-M symbol) |
Space group | I2/a |
Identification | |
Color | Grey |
Crystal habit | Massive |
Mohs scale hardness | 6 |
Luster | Earthy, dull |
Streak | White |
Diaphaneity | Transparent |
Optical properties | Biaxial |
Refractive index | nα = 1.524 nγ = 1.531 |
References | [1][2][3] |
Moganite is an oxide mineral with the chemical formula SiO2 (silicon dioxide) that was discovered in 1984.[2] It crystallises in the monoclinic crystal system. Moganite is considered a polymorph of quartz: it has the same chemical composition as quartz, but a different crystal structure.[3]
In 1994, the International Mineralogical Association (IMA) had disapproved it as being a separate mineral because it was not clearly distinguishable from quartz.[4] It has only recently (2007) been approved as a valid mineral by the CNMNC, the Commission on New Minerals, Nomenclature and Classification (part of the IMA).[5]
This mineral has been mainly found in dry locales such as Gran Canaria and Lake Magadi.[6] It has been reported from a variety of locations in Europe, India and the United States.[2] It was named for the municipality of Mogán on Gran Canaria.[3] Physically, it has a hardness of about 6, a dull luster and appears as a transparent gray in color.
References
- ^ Mineralienatlas
- ^ a b c Ralph, Jolyon, and Ida Ralph. "Moganite: Moganite Mineral Information and Data." MinDat. 2007. Aug. 2007 <http://www.mindat.org/min-2739.html>.
- ^ a b c http://webmineral.com/data/Moganite.shtml Webmineral data
- ^ Origlieri, Marcus. "Moganite: a New Mineral -- Not!" Lithosphere (1994). Aug. 2007 <http://geopress.rbnet.net/moganite.htm>.
- ^ Nickel, Ernest H., and Monte C. Nichols. "IMA/CNMNC List of Mineral Names." Materials Data. June 2007. Aug. 2007 http://www.geo.vu.nl/users/ima-cnmmn/MINERALlist.pdf Archived May 30, 2008, at the Wayback Machine
- ^ Heaney, Peter J., and Jeffrey E. Post. "The Widespread Distribution of a Novel Silica Polymorph in Microcrystalline Quartz Varieties." Science ns 255 (1992): 441-443. JSTOR. Aug. 2007. Keyword: moganite.