1. S6E5. Students will investigate the scientific view of how the earth’s surface is formed. c. Classify rocks by their process of formation. d. Describe processes that change rocks and the surface of the earth.

2. Rocks are: A solid made of one or more minerals and other materials.

3. Classifying Rocks: Rocks are classified based on how they were formed.

4. Identifying Rocks: Rocks are further identified by: Color Texture Mineral composition

5. Texture: Texture is the quality of a rock that is based on the sizes, shapes, and positions of the rock’s grains.

6. Composition: Composition is the chemical makeup of a rock. Composition can describe either the minerals or other materials in the rock.

7. Identifying Rocks: Rocks are further identified by: Color Texture Mineral composition

8. Grains: Particles of minerals that make up a rock. Texture is determined by grain, size, grain, shape, and grain pattern.

9. Grain Size: Some rocks have grains that are large and easy to see. These rocks are coarse grained. Other rocks have grains so small they are microscopic. These are fine grained rocks.

10. Grain Shape: Grains can be: Fine sand Crystals Fragments that can be smooth or jagged

11. Grain Pattern: Grains can lie flat in layers like a stack of pancakes. Some have patterns that look like waves or swirls Some resemble rows of beads. Others will have random patterns

12. No Visible Grain: Some rocks resemble pieces of glass. These rocks cooled very quickly so crystals did not have time to grow.

13. Mineral Composition: Since rocks are really combinations of minerals, geologists must slice their samples into very thin pieces to test which minerals are present.

14. Origins of Rocks: Rocks are classified by the way they are formed. Igneous rocks: formed from the cooling of molten rock. Sedimentary rocks: formed from sediments being compacted and cemented. Metamorphic rocks: existing rock that is changed by heat & pressure