Moganite

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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[edit]

  1. ^ Mineralienatlas
  2. ^ 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>.
  3. ^ a b c http://webmineral.com/data/Moganite.shtml Webmineral data
  4. ^ Origlieri, Marcus. "Moganite: a New Mineral -- Not!" Lithosphere (1994). Aug. 2007 <http://geopress.rbnet.net/moganite.htm>.
  5. ^ 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.
  6. ^ 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.

External links[edit]