1. REVIEW FOR GEOLOGY 141 CHEMISTRY WHIZ SHEET (Follow along on p. 61) If one knows the chemical formula for a particular mineral, with a little help from this sheet, one could determine which mineral group it belongs to without a lot of rote memorization, as follows: Colby Geology

2. If a mineral formula ends with O x, like Specular Hematite and Oolitic Hematite (Fe 2 O 3 ), Magnetite (Fe 3 O 4 ) or Corundum (Al 2 O 3 ), then that mineral belongs to the OXIDE group. OXIDES CORUNDUM OOLITIC HEMATITE SPECULAR HEMATITE MAGNETITE

3. If a mineral formula ends with OH, like Limonite (FeOOH) or Bauxite, then that mineral belongs to the HYDROXIDE group. HYDROXIDES BAUXITE LIMONITE

4. If a mineral formula ends with S x, like Chalcopyrite (CuFeS 2 ), Galena (PbS), Pyrite (FeS 2 ) or Sphalerite (Zn,FeS), then that mineral belongs to the SULFIDE group. SULFIDES CHALCOPYRITE GALENAPYRITE SPHALERITE

5. If a mineral formula ends with CO 3, like Calcite (CaCO 3 ), or Dolomite (Ca,Mg(CO 3 ) 2 ) then that mineral belongs to the CARBONATE group. CARBONATES DOLOMITECALCITE

6. If a mineral formula ends with F, Cl, Br, I, like Fluorite (CaF 2 ) or Halite (NaCl), then that mineral belongs to the HALIDE group. HALIDES HALITE FLUORITE

7. If a mineral formula ends with or includes SO 4, like gypsum CaSO 4 2H2O, then that mineral belongs to the SULFATE group. SULFATES GYPSUM

8. If a mineral formula is a single element, like Native Copper (Cu), then that mineral belongs to the NATIVE ELEMENTS. NATIVE ELEMENTS GOLD COPPER SILVER

9. The remainder of the minerals belong to the SILICATE Group, and the respective subgroup depends on how the silica tetrahedra (SiO 4 ) are attached within the mineral. SILICATE MINERALS

10. FRAMEWORK SILICATES include Orthoclase (KAlSi 3 O 8 ), Oligoclase and Labradorite (Ca,Na) (Al,Si) 4 O 8 and Quartz (SiO 2 ). Si:O ratio = 1:2 FRAMEWORK SILICATES FELDSPAR QUARTZ (SiO 2 )

11. SHEET SILICATES include Biotite, Chlorite and Muscovite. SHEET SILICATES BIOTITE MUSCOVITE

12. SINGLE CHAIN SILICATES include Augite. Si:O ratio = 1:3 CHAIN SILICATES AUGITE

13. DOUBLE CHAIN SILICATES include Actinolite and Hornblende. Si:O ratio = 1:2.75 CHAIN SILICATES ACTINOLITE HORNBLENDE

14. ISLAND SILICATES include Garnet, Olivine (Fe,Mg) 2 SiO 4 and Staurolite. Si:O ratio = 1:4 ISLAND SILICATES GARNET STAUROLITE OLIVINE