Unformatted text preview: Introduction to Mineralogy Mineralogy can be: Complex Difficult Boring Interesting Exciting Because... It's a mix of complex/new ideas, with massive amounts of rote memorization. Objectives
Three parts to class (originally three classes):
1. Learn chemical properties of minerals Crystallography spatial arrangement of atoms Crystal chemistry what atoms make up minerals and why 1. Analytical methods: Physical properties (this week's lab) visual observations Polarizing microscope Xray diffraction 1. Identify, classify and organize minerals Why study mineralogy? Minerals are chemical compounds that form from natural chemical/earth processes Minerals are basic building block of rocks Rocks provide record of earth history and are formed by earth processes Holistic Earth science: Earth history Earth processes Definition of Mineral
A naturally occurring, homogeneous solid, with a defined (but generally not fixed) chemical composition and an ordered atomic arrangement 1. Naturally occurring Why not synthetic (manmade)? E.g. diamonds Table salt (halite) Corian countertops (quartz) Others? 1. Naturally occurring Why not synthetic (manmade)? E.g. diamonds Corian countertops (quartz) Table salt (halite) Others? San Francisco Bay Great Salt Lake, Utah 2. Homogeneous solid Minerals can not be PHYSICALLY broken into new compounds Why solid? How about chemically "broken"? What would they break into? 3. Defined, but not fixed, composition The compositions of minerals are strictly defined (stoichiometry), but can vary between compositions For example: Calcite is CaCO3 but will also contain much Mg, Sr, Fe, Mn etc. Olivine is a group of two main minerals:
Fayalite (Fe2SiO4) Forsterite (Mg SiO ) 2 4 4. Ordered atomic arrangement Crystallography how atoms are arranged in space. This arrangement is the basis of crystallography For example: Aragonite (CaCO3) and Calcite (CaCO3) are different minerals but have identical compositions This is why minerals are referred to by name rather than formula Mineral names include both composition (chemistry) and crystallography ...
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- Spring '11