1. Igneous Rocks

2. Look at the words below. Pick 3 words you don’t know, 2 words you do know, and come up with 1 word that describes all the words below.

4. form from the cooling of molten rock (lava and magma).
Igneous Rocks
form from the cooling of molten rock (lava and magma).

5. Are lava and magma the same?
LAVA is molten material found on the surface of the earth.
MAGMA is molten material found beneath the surface of the earth.

6. Classified by Formation:
Extrusive Rock is formed from lava erupted onto Earth’s surface.
Exits the Earth
Basalt

7. Classified by Formation:
Intrusive Rock is formed when magma hardens beneath Earth’s surface.
Inside the Earth
Granite

10. Classified by Texture:
Fast Cooling Lava (Extrusive)
Fine-Grained, small crystals, more smooth
Slow Cooling Magma (Intrusive)
Coarse-Grained, large crystals, more rough

11. An intrusive igneous rock would have what type of texture? Why?
Coarse-Grained, large crystals. Smooth & rough.
It is hotter in the earth than on the outside of the earth so it takes longer for magma to cool down.

12. An extrusive igneous rock would have what type of texture? Why?
Fine-Grained or glassy texture
It is cooler on the surface of the Earth so the rocks can cool faster.

13. Classified by Mineral Composition
Mafic describes dark colored rocks because of magnesium and iron.
Felsic describes light colored rocks because of feldspar and silicon

14. Mineral Composition Igneous Rocks
Granite is made of:
Feldspar, Mica, Quartz, Hornblende
Rhyolite is made of:
Obsidian is made of:
Quartz, Iron, Magnesium

15. How do you use igneous rocks?
Tools Gravel Buildings Cleaning Streets Polishing Bridges Gardening

16. Classify igneous rocks according to their formation.
Where do they form AND made of magma or lava?
Intrusive (magma) and Extrusive (lava)
How do they cool?
Slow = Large crystals
Fast = Small or No Crystals
What they are made of (mineral composition)?
Mafic and Felsic

17. SAMPLE 1 = PUMICE
SAMPLE 2 = ANDESITE
SAMPLE 3 = OBSIDIAN
SAMPLE 4 = GRANITE
SAMPLE 5 = SCORIA
SAMPLE 6 = GABBRO
SAMPLE 7 = RHYOLITE
SAMPLE 8 = DIORITE
SAMPLE 9 = BASALT