EARTH231 Lecture Notes - Lecture 11: Valence Electron, Triclinic Crystal System, Crystallography
24 Feb 2015
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The study of the occurrence, formation, properties, composition, and classification of minerals. Explain how x mineral fits the definition of a mineral ((e. g. ) halite nacl salt) Albite (ca2+, na1+) (al3+, si4+) al si2o8. Ratio = 1:2 (ca, mg, fe)7 si8o22 (oh)2. K (mg, fe)3 (al si3o10) (oh)2 (mg, fe) sio3. Ca (mg, fe) si2o6 (k, na) al si3o8. 2ca al2 si o8(s) + na2o (l) + 2sio2(l) 6mg7 si8o22 (oh)2(s) + 7k2o(l) +7 al2o3(l) + 8h2o(l) Need to know reaction words for tests: silicification, hydration, desilicification. *reminder, sometimes al can sub in for si in the basic structural building blocks in the silicate tetrahedron. It occurs when al is beside si, with no brackets. Axbycz cations reducing in size order in the formula. Important aspects of the notation: balanced formulas have both cations and anions, brackets share the same spot in the crystal lattice (interchangeable) (mg, fe)2 sio4, brackets also equal the structural position, bonding.
