Minerals

Mineral - definition Naturally occurring Inorganic Solid Specific atomic composition Definite atomic structure

Mineral Identification 1. Hardness 2. Streak 3. Cleavage/Fracture 4. Luster 5. Specific Gravity 6. Color

Hardness Is measured by how easy it is to scratch. Geologists order the hardness by… 1. Scratched by a fingernail. 2. Scratched by a penny. 3. Scratched by a nail. 4. Scratched by a diamond. These are not all of the tools geologists use, but it will work for our experiment.

Mineral Identification Hardness – the ability to resist scratching; ranges from 1 (softest) to 10 (hardest)

Mineral Systems If space is not restricted, a mineral will exhibit a crystal pattern with a definite number of sides and specific angles.

Mineral Identification _________ – the color of the powdered form of a mineral Streak

Mineral Identification Cleavage (flat surfaces) or Fracture (no flat surfaces) – the way a mineral __________ breaks

Mineral Identification Fracture: ___________________ Ex. Quartz or obsidian

Mica is probably the best example as it splits into thin sheets. It is said to have one perfect cleavage.

Calcite and Galena cleave in three directions. They are said to have three good cleavages.

Not all minerals show cleavage. Those that don’t break along cleavage surfaces are said to have fracture.

Terminator Baby

Luster Refers to the way light reflects from the surface of the mineral. There are two types of luster, Metallic: looks like polished metal. Nonmetallic: does not look like polished metal. Nonmetallic can be shiny or dull.

Pyrite has metallic luster

Quartz has nonmetallic luster

Specific Gravity of a Mineral

One mineral property we will not use… COLOR

A mineral can be many different colors. Below is Mica.

Review

RAP

Discovery Channel : Minerals

SilicatesNon Silicates

COMMON MINERALS IN THE EARTH QUARTZ (Silica) SiO 2 CORUNDUM (Alumina) Al 2 O 3 HEMATITE Fe 2 O 3 CALCITE CaCO 3 DOLOMITE CaMg(CO 3 ) 2 GYPSUM CaSO 4 FLUORITE CaF 2 PYRITE FeS 2 OLIVINE (Mg,Fe) 2 SiO 4 PYROXENE (Mg,Fe)SiO 3 AMPHIBOLE (Ca 2 Mg 5 )Si 8 O 22 (OH) 2 FELDSPARS Albite NaAlSi 3 O 8 Orthoclase KAlSi 3 O 8 Anorthite CaAl 2 Si 2 O 8 KAOLINITE Al 2 Si 2 O 5 (OH) 4

Discovery Channel : Salt

Common minerals and their uses