MINERALS

Definition: Naturally occurring, Inorganic, Solid, Crystalline, specific chemical composition, regular repeating atomic arrangement

Chemical Composition - specific ratio of chemical elements

Common elements in rocks: Si, Al, O, Ca, Mg, H, C, Fe, Na, K

Structure

silicate structure - SiO₄ tetrahedron, isolated tetrahedra, single chain, double chain, sheet, 3-D framework

silicate minerals, isolated tetrahedra -olivine (Fe, Mg); single chain - pyroxene (Fe, Mg); double chain - amphibole (Fe, Mg, Ca); sheet - mica; biotite (Fe, Mg) or muscovite (K); 3-D framework - Feldspar (Ca, Na, K); Quartz (SiO₂)

Non-silicate minerals- calcite (CaCO₃), halite (NaCl); gypsum (CaSO₄)

Physical properties-luster, color, crystal shape, cleavage, fracture, hardness, specific gravity, other (fizz, magnetism, double refraction...)

Carefully define mineral. How does this relate to rocks? elements?  Characterize the difference between a mineral and natural glass.

Be able to identify a sketch of a silica tetrahedron, a single chain, a double chain, and a sheet structure. Give an example of a mineral which contains each type of structure.

Describe six techniques used in identification of an unknown mineral. Which are the most useful?

Why does the silica tetrahedron have the composition SiO₄ while quartz is SiO₂?

Briefly, but thoroughly, describe two physical properties that are distinctive, but only useful for a limited number of minerals (i.e. only work in rare occasions, but are really useful for those unique minerals).

Go back to Geology page