A few meteorites do contain rare grains of SiO2 including tridymite, quartz and cristobalite, but generally these grains are quite small and intergrown with other silicate phases. Some IVA irons contain a few blades of trydimite, but if you see a rock with several percent or more of quartz grains that are millimeter size or larger, it will not be a meteorite.
On Sat, Sep 23, 2017 at 4:46 PM, Abdelfattah Gharrad via Meteorite-list < meteorite-list@meteoritecentral.com> wrote: > Hello members, > > I really want to post my question about quartz longtimes ago, what I > learned that if one sees quartz on a stone then the stone is not meteorite. > in my knowledge there are different types of quartz and whose chemical > formula is SiO2. > > habitually no quartz in the meteorites but if there is in a meteorite then > it is a rare stone and whose classification differs from other meteorites > and testimony of another planet it's just opinion. > > I think that the meteorites have chemical compositions like the > terrestrial stones (magmatic, volcanic ...). the probability that a > meteorite contains SiO2 is not zero. > > if there is a clarification please. > > Thanks, > Abdelfattah. > ______________________________________________ > > Visit our Facebook page https://www.facebook.com/meteoritecentral and the > Archives at http://www.meteorite-list-archives.com > Meteorite-list mailing list > Meteorite-list@meteoritecentral.com > https://pairlist3.pair.net/mailman/listinfo/meteorite-list > -- Alan Rubin Institute of Geophysics and Planetary Physics Department of Earth, Planetary, and Space Sciences University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 USA office phone: 310-825-3202 fax: 310-206-3051 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html
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