1. Types of Rocks

2. Rock Classification
Composition- the chemical makeup of a rock by either:
The minerals in the rock or
other material in the rock.
Texture – the quality of a rock based on the sizes, shapes, and position of the rocks grains:
fine grained- sedimentary, igneous, or metamorphic
Medium grained- sedimentary, metamorphic
Coarse grained - sedimentary, igneous

3. Sedimentary Rock
Sedimentary rock – rocks formed when sediment was deposited; buried sediment is compacted and cemented by the weight of overlying layers of sediment.
Sediment - small particles of soil and weathered rock
Fossils – formed in sedimentary rock from the remains of prehistoric plants and animals

4. Sedimentary Rock
Stratification is the process in which sedimentary rocks are arranged in layers
Examples: limestone (formed from fossils) and coal

5. Igneous Rock Igneous means fire
Igneous rocks form when magma rises or erupts from a volcano and cools
The types of minerals in the magma and the speed at which it cools determines what kind of igneous rock is formed.
Light-colored rocks are less dense than dark-colored rocks

6. Igneous Rock
Intrusive Igneous rock – rock formed from the cooling and solidification of magma beneath the Earth’s surface
Extrusive Igneous rock – rock that forms as a result of volcanic activity at or near the Earth’s surface
Examples: granite

7. Metamorphic Rock
Metamorphic rocks are formed when intense heat and pressure change the composition, structure, or texture of rocks over time.
If the temperature or pressure of the environment is different from the one in which the rock initially formed, the rock will undergo metamorphism
Two textures: foliated (planes or bands) and nonfoliated

8. Metamorphic Rock Examples of foliated rock: slate, phyllite, gneiss
Examples of nonfoliated rock: marble, quartize
All three types of rock can be changed by heat, pressure, or both.