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Ge 101. Introduction to Geology and Geochemistry. Lecture 2 Crystal Structure of Minerals. Image 2.1. Cleavage planes and number of cleavage directions. Silicate structure. Specimen. Mineral. Chemical formula. Isolated tetrahedra. 1 plane. (Mg,Fe) 2 SiO 4. Olivine.
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Ge101. Introduction to Geology and Geochemistry Lecture 2 Crystal Structure of Minerals
Cleavage planes and number of cleavage directions Silicate structure Specimen Mineral Chemical formula Isolated tetrahedra 1 plane (Mg,Fe)2SiO4 Olivine 2 planes at 90° Single chains (Mg,Fe)SiO3 Pyroxene 2 planes at 60° and 120° Double chains Ca2(Mg, Fe)5Si8O22(OH)2 Amphibole Sheets 1 plane Muscovite: KAl2(AlSi3O10)(OH)2 Micas Biotite: K(Mg, Fe)3AlSi3O10(OH)2 Three-dimensional framework 2 planes at 90° Orthoclase feldspar: KAlSi3O8 Feldspars Plagioclase feldspar: (Ca, Na) AlSi3O8 Image2.2