1. Igneous Rocks

2. Rock A group of minerals bound together in some way
Minerals= ingredients
Rock= cookie

3. 2 Kinds of Igneous Rocks

4. 2 Kinds of Igneous Rocks Intrusive/ Plutonic (within):
Formed underground from magma
Usually coarse-grained texture  Large crystals
Slow cooling process
Extrusive/ Volcanic (outward/exit):
Formed on surface from lava, dust, ash
Usually fine-grained texture  Small crystals
Rapid cooling process

5. 2 Kinds of Magma/Lava Felsic: Light in color Rich in: Al, K
Usually contains feldspar, quartz, muscovite
Ex: Granite, Rhyolite
Mafic:
Dark in color
Rich in: Fe, Mg
Contains olivine, feldspar, biotite
Ex: Gabbro, Basalt

6. Texture  *DRAW IN NB*  Crystals big enough to see with eyes
Coarse-grained:
Crystals big enough to see with eyes
Magma cools slowly underground  Crystals have time to grow (more time = larger crystals)
Fine-grained:
Crystals are small, instruments are needed to see them
Magma/lava cools rapidly on surface  Crystals have no time to grow (less time = smaller crystals)
 *DRAW IN NB* 

7. Texture
Porphyritic:
Coarse-grained crystals surrounded by fine-grained crystals
Magma cools slowly underground, then suddenly begins cooling rapidly

8. Summary What are the two types of igneous rocks
How do you know an igneous sample is mafic or felsic?
What does the texture of an igneous rock tell you?