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| System: | Orthorhombic |
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| Name: | Named in honour of Dr. Friedrich Seifert (1941- ), founding Director of the Bayerisches Geoinstitut (Bavarian Geoinstitute) at Bayreuth, Germany. |
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The densest and hardest polymorph of silica found in nature so far, with a structure similar to that of alpha-PbO2. Found first in the Shergotty meteorite, and since then in several other Martian meteorites. Stable only above pressures of 780 kilobars, so it could theoretically also form in the Earth's mantle at depths over 1,700 km, if any free silica is present.
Classification of Seifertite |
| IMA status: | Approved 2004 |
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| Nickel-Strunz 10th (pending) edition ID: | 4.DA.50
4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates) D : Metal: Oxygen = 1:2 and similar A : With small cations: Silica family |
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| Dana 8th edition ID: | 75.1.6.
75 : TECTOSILICATES Si Tetrahedral Frameworks 1 : Si Tetrahedral Frameworks - SiO2 with [4] coordinated Si |
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| mindat.org URL: | http://www.mindat.org/min-26715.html Please feel free to link to this page. |
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Type Occurrence of Seifertite |
| Type Locality: | Shergotty Martian meteorite, Gaya District, Bihar, India |
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| General Appearance of Type Material: | lamellae occurring in composit silica grains |
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| Geological Setting of type material: | Presumably formed by impact shock in basaltic Mars rock. |
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Occurrences of Seifertite |
| Geological Setting: | Meteorites derived from Martian basalt. |
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Physical Properties of Seifertite |
| Density (calculated): | 4.294 g/cm3 |
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Crystallography of Seifertite |
| Crystal System: | Orthorhombic |
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| Class (H-M): | mmm (2/m 2/m 2/m) - Dipyramidal |
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| Space Group: | Pbcn {P21/b 2/c 21/n} |
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| Cell Parameters: | a = 4.097(1) Å, b = 5.0462(8) Å, c = 4.4946(8) Å
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| Ratio: | a:b:c = 0.812 : 1 : 0.891 |
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| Unit Cell Volume: | V 92.92 ų |
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| Z: | 4 |
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Chemical Properties of Seifertite |
| Formula: | |
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| Essential elements: | O, Si |
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| All elements listed in formula: | O, Si |
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| Empirical Formula: | |
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Relationship of Seifertite to other Species |
Related Minerals - Nickel-Strunz Grouping):
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Other Names for Seifertite |
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Other Information |
| Health Warning: | No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care. |
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References for Seifertite |
Reference List:
- + | A. El Goresy, P. Dera, T.G. Sharp, C.T. Prewitt, M. Chen, L. Dubrovinsky, B. Wopenka, N.Z. Boctor, R.J. Hemley (2008): Seifertite, a dense orthorhombic polymorph of silica from the Martian meteorites Shergotty and Zagami. European Journal of Mineralogy 20, 523-528.
U. Bläß, F. Langenhorst (2011): High-pressure phase transformation of SiO2 polymorphs to Seifertite. Joint Meeting of the DGK, DMG and ÖMG, Salzburg, Austria, September 20-24, 2011; Abstracts Volume, p. 46.
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Internet Links for Seifertite |
| Search Engines: |
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| External Links: | Look for Seifertite on WebmineralLook for Seifertite on Athena MineralogyLook for Seifertite on WikipediaLook for Seifertite on Mineralien AtlasRaman and XRD data at RRUFF projectAmerican Mineralogist Crystal Structure Database |
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| Jobs: | Mining & Geology Jobs |
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Localities for Seifertite |
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