Silica mineral, rare monoclinic polymorph of quartz
Not to be confused with Morganite (gem).
Moganite
Moganite. Medio Almud ravine, Mogán, Gran Canaria, Spain. Height 5cm.
General
Category
Tectosilicate, quartz group
Formula (repeating unit)
SiO2
IMA symbol
Mog[1]
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
Specific gravity
2.52 – 2.58
Optical properties
Biaxial
Refractive index
nα = 1.524 nγ = 1.531
References
[2][3][4]
Moganite is an oxide mineral with the chemical formula SiO2 (silicon dioxide) that was discovered in 1976. It was initially described as a new form of silica from specimens found in the Barranco de Medio Almud, in the municipality of Mogán on the island of Gran Canaria, in the Canary Islands (Spain),[5] receiving in a later work the name derived from this locality.[6] In 1994 the International Mineralogical Association decided to disapprove it as a valid mineral, since it was considered indistinguishable from quartz.[7] Subsequent studies allowed the IMA to rectify it in 1999, accepting it as a mineral species.[8]
It has the same chemical composition as quartz, but a different crystal structure.[4]
This mineral has been mainly found in dry locales such as Gran Canaria and Lake Magadi.[9] It has been reported from a variety of locations in Europe, India and the United States.[3] Physically, it has a Mohs hardness of about 6, a dull luster and appears as a semitransparent gray in color.
^"Mineralienatlas Lexicon – Mogánite". Mineralienatlas. Retrieved 13 August 2023.
^ abRalph, Jolyon; Ralph, Ida (2007). "Moganite: Moganite Mineral Information and Data". MinDat. Retrieved 1 August 2007.
^ ab"Webmineral data".
^Flörque, O.W.; Jones, J.B.; Schmincke, H.U. (1976). "A new microcrystalline silica from Gran Canaria". Zeitschrift für Kristallographie. 143: 156–165.
^Flörque, O.W.; Flörque, U.; Giese, U. (1984). "Moganite, a new microcristaline silica-mineral". Neues Jahrbuch fur Mineralogie (Abhandlungen). 149: 325–336.
^Origlieri, M., 1994. "Moganite: a New Mineral – Not!" Lithosphere. Aug. 2007 http://geopress.rbnet.net/moganite.htm
^Grice, Joel D.; Ferraris, Giovanni (2000). "New minerals approved in 1999 by the commission on new minerals and mineral names, International Mineralogical Association". The Canadian Mineralogist. 38 (1): 245–250. Bibcode:2000CaMin..38..245G. doi:10.2113/gscanmin.38.1.245.
^Heaney, Peter J.; Post, Jeffrey E. (1992). "The Widespread Distribution of a Novel Silica Polymorph in Microcrystalline Quartz Varieties". Science. 255 (5043): 441–443. Bibcode:1992Sci...255..441H. doi:10.1126/science.255.5043.441. PMID 17842895. S2CID 32497622.
Moganite is an oxide mineral with the chemical formula SiO2 (silicon dioxide) that was discovered in 1976. It was initially described as a new form of...
of quartz and moganite. These are both silica minerals, but they differ in that quartz has a trigonal crystal structure, while moganite is monoclinic...
consisting of fine intergrowths of both quartz, and its monoclinic polymorph moganite. Other opaque gemstone varieties of quartz, or mixed rocks including quartz...
cryptocrystalline, consisting of fine intergrowths of the silica minerals quartz and moganite. Its bands are parallel to one another, as opposed to the more chaotic...
(variety of spinel) Chalcedony (cryptocrystalline variety of quartz and moganite) Chiastolite (variety of andalusite) Chlorastrolite (variety of pumpellyite-(Mg))...
1524/zkri.1959.112.1-6.409. Miehe G, Graetsch H (1992). "Crystal structure of moganite: a new structure type for silica". European Journal of Mineralogy. 4 (4):...
Important ones include: α-quartz, β-quartz, tridymite, cristobalite, moganite, coesite, and stishovite. Classical examples of polymorphism are the pair...
of silica, consisting of fine intergrowths of the minerals quartz and moganite. Chrome chalcedony (known as mtorolite, mtorodite or matorolite) occurs...
identifier 9.GA.05 (zeolites with T5O10 units – the fibrous zeolites); mogánite (SiO2), but it has Nickel-Strunz identifier 4.DA.20 (oxides with small...