1. I. How to Identify Rocks?
Scientist study rock by looking at two types of criteria: composition and texture.
1. Composition
The chemical makeup of a rock.

2. I. How to Identify Rocks?
Scientist study rock by looking at two types of criteria: composition and texture.
2. Texture: Is based on the size shape and position of mineral grain/crystals.

3. II. 3 Ways Magma Forms

4. III. Texture
Igneous pattern
Metamorphic pattern
Sedimentary pattern

5. A. Texture of Igneous Rock
Intrusive Igneous Rock
Rock formed from the cooling and solidification of magma beneath the Earth’s surface.
Slow cooling results in the formation of large crystals.
(Coarse-grained Texture)
Interactive Rock Sim

6. A. Texture of Igneous Rock
2. Extrusive Igneous Rock
Rock that forms as a result of volcanic activity at or near the Earth’s surface
Fast cooling results in the formation of small crystals.
(Fine-grained Texture) -
Interactive Rock Sim

7. Four Igneous Rocks Web Activity

8. B. Composition of Igneous Rock
1. Felsic Rock
Light colored rocks.
Composed of aluminum, potassium, silicon, and sodium.
2. Mafic Rock
Dark colored rocks.
Composed of calcium, iron, and magnesium.
Fine-grained
Course-grained
Course-grained
Fine-grained