1. What is igneous rock? Any rock that forms from magma or lava
Classified by origin, texture, and mineral composition
EX: (your experience, new question, or WU answered.)

2. Origin: what is extrusive?
Extrusive: formed from lava that erupted onto the Earth’s surface.
Basalt most common extrusive rock.
EX: (your experience, new question, or WU answered.)

3. Origin: what is intrusive?
Intrusive: formed when magma hardened beneath the earth’s surface.
Granite is the most common intrusive rock.
EX: (your experience, new question, or WU answered.)

4. What determines texture?
Rapidly cooled lava = fine-grained igneous rock with small crystals
Slow cooled magma = coarse-grained igneous rock with large crystals
EX: (your experience, new question, or WU answered.)

5. What is the most common mineral of the Earth?
Most of Earth’s minerals contain silica.
EX: (your experience, new question, or WU answered.)
Why does Mrs. Clark have a picture of sand?

6. How does the mineral composition (silica) affect the color of igneous rocks?
The silica content of magma and lava affects the types of rock they form
less silica = dark colored rocks
More silica = light colored rocks

7. What is igneous rock used for?
Tools, building materials, art
Egyptians
3,500 years age
Mt Rushmore
National Memorial.
South Dakota, USA
180 years ago
Incas of Peru
600 years ago