1. Rock Classification

2. What is a Rock?
A MIXTURE OF MINERALS

3. All are rocks but look different

4. Reasons?

5. All are from cooled lava
diorite
All are from cooled lava
peridotite
obsidian

6. All are from particles “glued” together
Chert
Breccia
Limestone

7. All these have been pushed down into earth and reheated
gneiss
hornfels

8. All rocks are classified by how they are formed (made).
(Remember this!)

9. What are the three kinds of rock:
Igneous:
When lava or magma cools and hardens
Sedimentary:
When particles are “glued” together
Metamorphic:
When rocks are changed by heat and pressure in earth

10. Igneous rocks What are they? Why do they look different?
From cooled magma (underground) or lava (above ground)
Why do they look different?
Cool at different rates
Intrusive – cool inside Earth
(slow cooling= big crystals)
Extrusive – cool outside Earth’s interior (fast cooling = small or no crystals)

11. Which kind of igneous rock will be formed?

12. More differences: Color of Igneous Rock
Rocks high in silica are lighter in color
Rocks low in silica are darker in color
Silica- A chemical compound that makes most of the Earth's rocks. Silica occurs in different crystalline forms. It is also the main chemical compound in sand. Silica is used to make glass, concrete, and other materials.

13. Sedimentary rocks What are they? Why do they look different?
Made of sediments cemented together
Why do they look different?
Made of different things
Clastic – made of particles from erosion
Chemical – made of dissolved materials
Organic – made of living material

14. Which kind of sedimentary rock will be formed?

15. Clastic Sedimentary rock is named according to chunk size
Pebbles – conglomerate
Sand – sandstone
Mud – mudstone (may contain fossils)
Shell particles – limestone

16. Metamorphic rock What are they? Why do they look different?
Have been changed by heat and pressure underground
Why do they look different?
Foliated – layers form from pressure in one direction
Non-foliated – no layers form – pressure comes from all directions

17. What kind of metamorphic rock is formed?

18. Metamorphic Rock Some examples: Limestone → marble →
Graphite (carbon)→ Diamond →

19. Check yourself: Which kind of rock?

20. Rock Cycle Processes
Describe each of the following in your own words as we watch the animation on the following slide:
Crystallization
Weathering and erosion
Transportation of sediments
Deposition of sediments
Compaction and cementation of sediments
Uplifting
Metamorphism
Melting

21. The Rock Cycle!
Animation!