HTML University

Science Dept.

Geology and Soils GEO 100 Notes
Minerals

1. Definition: A naturally occuring inorganic material with a definite internal order and arrangement of its constituent atoms having definite chemical and physical properties (which may vary within known limits)

2. Physical Characteristics
   1. Crystal Form: The ability of a specific chemical substance to crystallize with more than one type of structure is known as Polymorphism

   2. Habit

   3. Luster
      1. Metallic: use color eq pale brassy metallic
      2. Non-metallic: for example, adamantine, vitreous, dull or earthy

   4. Color

   5. Streak

   6. Hardness: Mohs Relative Hardness Scale
      1. Talc
      2. Gypsum
      3. Calcite
      4. Fluorite
      5. Apatite
      6. Orthoclase
      7. Quartx
      8. Topaz (also Beryl)
      9. Corundum
      10. Diamond

   7. Cleavage: 4 directions; 3 dir at right angle; 3 dir not right angle; 2 dir right angle; 2 dir not right angle; basal

   8. Fracture

   9. Specific Gravity & Heft

   10. Magnetic

   11. Touch or Feel

   12. Smell and Taste

3. Mineral Structure
   1. Compounds

   2. Isomorphism: tendency for 2 or more ions to substitute for one another in a continuous series

   3. Ionic bond

   4. Covalent bond

   5. SiO₄^{4 -} tetrahedra

4. Silicate Structures
   1. Nesosilicates: Olivine (Ol)

   2. Sorosilicates: Epidote

   3. Inosilicates (single chain): Augite (Pyrox)

   4. Inosilicates (double chain): Hornblende (Amphib)

   5. Phyllosilicates (sheet silicates): Micas

   6. Tectosilicates: Quartz, Feldspar

5. Mineral Families
   1. Native Elements: Gold, Sulfur

   2. Oxides: H₂O, SiO₂, Al₂O₃

   3. Halides

   4. Nitrates

   5. Carbonates: Calcite

   6. Borates

   7. Sulfates

   8. Chromates

   9. Wolframites

   10. Phosphates

   11. Vanadates

   12. Silicates
       1. Olivine
       2. Epidote
       3. Beryl
       4. Tourmaline
       5. Pyroxenes
       6. Amphiboles
       7. Micas
       8. Feldspars

6. Rock Forming Minerals
   1. Quartz

   2. Micas: Muscovite, Biotite

   3. Potassium Feldspars (Kfsp): Orthoclase

   4. Plagioclase Feldspar: Na to Ca

   5. Ferromagnesians
      1. Olivine
      2. Pyroxenes: Augite
      3. Amphiboles: Hornblende
      4. Biotite

   6. Clays: Kaolinite

   7. Calcite

   8. Dolomite

   9. Halite

   10. Gypsum