1. Classifying Rocks
CH 3 Prentice Hall p

2. Rocks
Are made of mixtures of minerals and other materials, although some may contain only a single mineral.
Granite
Quartz
Feldspar,
Mica
Hornblend 2

3. Characteristics (brainstorm)
Group A
Group B
Group C
Rock Color
Texture
Luster
Group D
Group E
Group F
Density
Hardness
Porous

4. Texture Size, shape and pattern of rock grains.
Grains- particles of minerals or other rocks.

5. Texture (Grain Size) Course Grained- Large and easy to see.
Fine Grained- small. 5

6. Texture (Grain Shape) Grains vary widely. Tiny particles of sand.
Look like seeds
Crystals
Smooth / rounded
Jagged 6

7. Texture (Grain Pattern)
Grains often form patterns.
Some lie in flat layers.
Rows of grains.
Random grains. 7

8. Texture (No Visible Grain)
Have no grain.
They cool very quickly when they form, gives the rock a smooth, shiny texture like thick glass. (obsidian)
Or made out of extremely small particles of silica that settle out of water. (flint) 8

9. Origin 3 Groups- refers to how the rocks formed. Igneous
Forms from cooling molten rock.
Magma- below the surface.
Lava- above the surface.
Sedimentary
Forms from particles of other rocks, remains of plants and animals that are pressed and cemented together.
Metamorphic
Forms from pre-existing rock, deep underground.
Changes rock with heat, pressure and chemical reactions.

10. Mineral Composition
Use a microscope to look at the size & shape of crystals to ID (identify) minerals in the rock.
Acid test- tests for carbonates.
Magnetic Test- tests for iron and nickel.

11. Rock Cycle
Igneous
Sedimentary
Pressure
Metamorphic
Molten
Material