ERS120H5 Lecture Notes - Lecture 5: Pyrite, Feldspar, Covalent Bond
22 Jan 2016
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Document Summary
Spatial distributions of electron (wave function) orbitals around atoms fix how atoms bond together. Definite but not necessarily fixed chemical composition. Classified by chemical composition and crystal structure. Minerals are made of cations (+) and anions (-) bonded together. Common ions in earth"s crust: o = most common anion and si, al, fe, ca, na, #1: mafic silicate minerals: contain fe & mg, and are dark in colour (example: olivine, pyroxene, biotite/ mica/ pyroxene, hornblende/amphibole) #2: felsic silicate minerals: don"t contain fe or mg and are light in colour (example: fledspars, clays, muscovite/mica, quartz) Crystal structure: composed of single of multiple elements held together by chemical bonds: An ionic bond forms between a positive ion of sodium and chloride, a negative ion of chlorine produces halite nacl, when sodium gives up one electron to chloride, so that both have filled shells. In a ball and stick model of halite, the balls are ions and the sticks are chemical bonds.
