1. LEQ: What characteristics do geologists observe to classify, group, and identify rocks? Part 2
Key Terms: texture, grain, igneous rock, sedimentary rock, metamorphic rock

2. Studying Rock Samples Review
When studying a rock sample, geologists observe the 3 characteristics of the rock.
Color
Texture
Mineral Composition (

3. Using these characteristics, geologists can classify and group rocks according to how and where the rock forms. (

4. Groups of Rocks Three major groups of rocks: Igneous Rocks
Sedimentary Rocks
Metamorphic Rocks
Each group forms in a different way.

5. Igneous Rocks Form from the cooling and hardening of molten rock.
Either magma (below Earth’s surface) or
Lava (above Earth’s surface)
How Igneous Rocks form

6. Sedimentary Rocks
Form when particles of other rocks or the remains of plants and animals are pressed and cemented together.
Form in layers below Earth’s surface.
Observe how sediment is deposited
Observe how sediment is cemented

7. Metamorphic Rocks
Form when an existing rock is changed by heat, pressure, or chemical reactions.
Form deep under Earth’s surface
Observe how heat and pressure change a rock into a metamorphic rock.

8. Our Quia Class Page Quia Practice
Link to our Quia class page, and log in.
Try the columns activity until you can match the type of rock with the processes without any problem.
When complete, try some of the other activities focused towards our current chapter on Rocks.
Our Quia Class Page