1. Igneous Rocks 6th Grade Science
Mrs. Pancake Contact Teacher Summer 2003

2. So, What’s the difference?
How are they formed?
Lava
Magma
So, What’s the difference?

3. Lava Magma Magma: molten material inside the earth’s surface.
Lava: molten material outside the earth’s surface.

4. Intrusive Rocks
Magma
Gabbro Diorite
Granite Peridotite

5. When magma underneath the surface cools, Intrusive Rocks are formed
When magma underneath the surface cools, Intrusive Rocks are formed. They cool slowly, allowing visible crystals to form.

6. Texture Large,Visible Crystals Coarse-Grained Close up of Granite
Close up of Diorite
Coarse-grained texture can also be called phaneritic texture.

7. Extrusive Rocks
Lava

8. When the lava from a volcano cools and hardens, Extrusive rocks are formed. The lava cools too quickly for visible crystals to form.

9. Texture 1. Very rapid cooling a. No Crystals---Shiny---Glassy
b. No Crystals---Holy---Vesicular
rapid gas escaping
Close-up of Obsidian

10. Texture Close-up of Basalt 2. Quick Cooling
a. Small crystals---fine grained
Close-up of Rhyolite

11. Credits Basalt image, Pumice image, Rhyolite image, Obsidian image:
Magma image:
Granite image:
Volcano:
Lava image: :

12. Igneous rock creation image:
igneous_formation.htm
Diorite image:
Gabbro image:
Peridotite image:
Magma image:
Phaneritic texture image:

13. Close-up of Rhyolite: http://www. geolab. unc
Close-up of Basalt:
Close up of Obsidian:
Close up of Diorite:
Close up of Granite: