Lipscombite
{{Infobox mineral
| name = Lipscombite
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| image = Lipscombite sample.jpg
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| caption = Lipscombite: Small green crystals on quartz, Harvard Museum of Natural History
| category = Phosphate minerals
| formula = (Fe2+,Mn2+)(Fe3+)2(PO4)2(OH)2
| strunz = 8.BB.90
| dana = 41.10.02.01
| system = Tetragonal
| class = Trapezohedral (422)
(same H-M symbol)
| symmetry = P43212
| unit cell = a = 5.37, c = 12.81 [Å]; Z = 4
| molweight = 391.27 g/mol
| color = Green gray, olive green, black.
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| gravity = 3.68
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| opticalprop = Translucent to opaque
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Lipscombite (Fe2+,Mn2+)(Fe3+)2(PO4)2(OH)2[http://www.mindat.org/min-2412.html Lipscombite on Mindat][http://www.webmineral.com/data/Lipscombite.shtml Lipscombite data on WebMineral] is a green gray, olive green, or black. phosphate-based mineral containing iron, manganese, and iron phosphate.
Lipscombite is often formed at meteorite impact sites where its crystals are microscopically small, because crystal-forming conditions of pressure and temperature are brief.
In the Classification of non-silicate minerals lipscombite is in the lipscombite group, which also includes zinclipscombite. This group is within the non-silicate, category 8, anhydrous phosphates, lazulite supergroup.
Discovery
The mineral lipscombite was first made artificially and then found in nature. It was named after chemist William Lipscomb by the mineralogist John W. Gruner who first made it artificially.
While investigating the stability relations of iron oxides small, black, shiny crystals were obtained when a spherical iron pressure-temperature vessel was contaminated with phosphorus. The x-ray powder diffraction pattern was similar to lazulite, but unknown.
Gruner, a mineralogist at the University of Minnesota, gave Lipscomb, a chemistry professor there, the crystals for Lewis Katz and Lipscomb to determine the atomic structure using single-crystal x-ray diffraction. They initially called the mineral iron lazulite.
References
{{reflist|refs=
Structures and Mechanisms: From Ashes to Enzymes (Acs Symposium Series) Gareth R. Eaton (Editor), Don C. Wiley (Editor), Oleg Jardetzky (Editor), American Chemical Society, Washington, DC (2002) (Autobiographical sketch by William Lipscomb, 14 pp. (Lipscombite: p. xvii). This chapter is online at [http://pubs.acs.org/isbn/9780841237360 pubs.acs.org]. Click PDF symbols at right.
Katz L., Lipscomb W. N. The crystal structure of iron lazulite, a synthetic
mineral related to lazulite: Acta Crystallographica, 4, 345–348 (1951).
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External links
Gallery of [http://www.mindat.org/gallery.php?min=2412 lipscombite pictures] at mindat.org.
{{Commons category|Lipscombite|position=left}}
Category:Manganese(II) minerals
Category:Minerals in space group 96
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