1. Minerals & Rocks

2. Minerals
A naturally formed, inorganic solid with crystal structure and definate chemical composition.
The substance was not formed by or from living things such as plants or animals
Made from Chemical elements or compounds
Minerals can be identified by their physical and chemical properties
Luster, Streak, Crystal, Hardness, Density and Structure.

3. Luster The way a mineral reflects light Metallic Luster
hard, shiny
Nonmetallic Luster
shiny, glassy, waxy, pearly, earthy (dull)

4. Streak The streak is the color of the mineral in powdered form.
The streak is found by rubbing a fresh corner of the mineral across a white, unglazed streak plate
Some metallic minerals leave behind a powder that is not the same color as the mineral.
The color of the mineral is not always the same as the streak! Streak is more reliable.

5. Crystal Structure
A regularly shaped solid formed by an ordered pattern of atoms
Examples include: Six sided, cubic, rectangular, sheets, fibers

6. Hardness A measure of how easily a mineral can be scratched.
Minerals can be tested by scratching the unknown mineral with the edge or point of other materials of known harness

7. Mohs Scale of Hardness

8. Density
Can be found by either dividing the mass of a sample by its volume or flotation
Water’s density is 1 g/mL
A substance will sink in water if it is more dense than 1g/mL and float if it is less dense than 1g/ML

9. Rocks Nearly all rocks are composed of one or more minerals
Geologists classify rocks according to how they were formed
Igneous rocks form from lava when it reaches the surface, cools and solidifies
Sedimentary rocks result from the compaction and cementing of layers of sediment
Metamorphic rocks form when other types of rocks are changed by heat and/or pressure

10. Igneous Rocks The result of the solidification of magma or lava
Most lack layering, however successive lava flows can form a layered rock structure
Those that cool slowly, deep within Earth, are composed of large crystals
Those that cool faster, at or near the Earth’s surface, have smaller or no visible crystals

11. Igneous Rock Formation

12. Igneous Rock Classification

13. Sedimentary Rocks
Most are composed of the weathered remains of other rocks
Usually are formed by the compression and cementing of particles of sediment
Generally exist as a thin layer over metamorphic and igneous rocks

14. Sedimentary Rock Characteristics
Fragmental rocks are made up of different sized particles such as shale, sandstone and conglomerate (composed of pebbles or larger stones held together by natural cement)
Organic sedimentary rock contain the accumulation of plant and animal remains
Fossils are commonly found
Chemical sedimentary rocks are deposited by the settling of materials from solution in seawater
This occurs during the evaporation of seawater and when chemical reactions in the water form compounds that settle
Rock Salt is an example

15. Sedimentary Rock Classification

16. Metamorphic Rocks
Form when sedimentary and igneous rocks are changed by heat and/or pressure
The only kind of rock that forms directly from another rock
Metamorphism may cause structures, such as layering, to become distorted or to disappear
It also may cause new minerals to form, and/or crystals to grow
Most are formed deep within the Earth and pushed to the surface when mountains are formed

17. Metamorphic Rock Classification
Texture
Appearance and feel of the rock surface
Grain Size
Composition
Type of Metamorphism

18. Metamorphic Rock Classification

19. The Rock Cycle
Natural changes in rocks and rock material that takes place at the Earth’s surface and within Earth
Nearly all rocks are made from the remains of other rocks
Rocks are classified based of their origin
Rocks can change in response to changing conditions at the surface or within Earth

20. The Rock Cycle