Rocks & Minerals Review

Flashcards for Rocks and Minerals Review

Mineral

A substance with a definite chemical composition, inorganic nature, solid form, crystalline structure, and natural occurrence.

Hardness

Resistance to being scratched.

Moh's Scale of Hardness

Scale from 1-10 that measures a mineral's hardness.

Streak

The color of a mineral's powder.

Luster

Shine from unweathered surface. Can be metallic (shiny like metal) or non-metallic (dull or glassy).

Cleavage

Breaks along smooth, parallel sides.

Fracture

Uneven breaking surfaces.

Graphite

Pencil lead, lubricants. Composition: C.

Galena

Ore of lead, batteries. Composition: PbS.

Magnetite

Ore of iron, steel. Composition: Fe304.

Pyrite

Ore of sulfur. Composition: FeS2.

Hematite

Ore of iron, jewelry. Composition: Fe203.

Talc

Ceramics, paper. Composition: Mg3 Si4010 (OH)2.

Sulfur

Sulfuric acid. Composition: S.

Selenite gypsum

Plaster of paris, drywall. Composition: CaSO4 2H20.

Muscovite mica

Paint, roofing. Composition: KAl3 Si30 10(OH)2.

Halite

Food additive, melts ice. Composition: NaCl.

3 Rock Types

Igneous, sedimentary, and metamorphic.

Rock Cycle

Process where any rock type can change into any other rock type.

Sedimentary Rocks

Formed due to compaction and cementation of rock particles. Divided into clastic, chemical/crystalline, and bioclastic types.

Clastic

From other rock pieces.

Chemical / Crystalline

From solution.

Bioclastic

From organic materials.

Sedimentary Rocks Characteristics

Layers of sediments (strata), visible sediments, fossils or shells, composed of only one mineral.

Igneous Rocks

Form when molten rock cools and hardens.

Intrusive (plutonic)

Form underground, cool slowly, large crystals (coarse-grained).

Extrusive (volcanic)

Form above ground, cool quickly, small or no crystals (fine-grained or glassy).

Igneous Rocks Characteristics

Glassy, vesicular texture (gas pockets), interconnected mineral crystals, multiple mineral composition.

Metamorphic Rocks

Form due to heat and pressure (recrystallization).

Foliated

Mineral crystals are aligned (banding is when minerals separate into stripes).

Non-foliated

Interconnected mineral crystals.

Regional Metamorphism

Large area of heat and pressure due to plate collision.

Contact Metamorphism

Small area of heat due to hot fluids.

Metamorphic Rocks Characteristics

Foliation (minerals flatten and line up), banding (stripes of minerals), intergrown mineral crystals, foliated mica, garnets.