1. Rocks and Erosion
Chapter 8 L4 and L5

2. Lesson 3 Ch8 Minerals pg 303
A mineral is a nonliving, naturally occurring solid that has its own regular arrangement of particles in it.
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3. Where are they found?
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4. Where are they found? Minerals are found in soil and rocks.
Although many different minerals exist, only a few dozen make up most of the rocks on Earth
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5. What does minerals make?
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6. Properties of minerals pg 304
There are more than 4,000 kinds of minerals.
Certain properties help scientists identify minerals.
These properties are hardness, luster, color, streak, shape, and magnetism. Sometimes smell.
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7. Hardness
Scientists test a mineral’s hardness by finding out how easily it can be scratched.
Use a chart called the Mohs scale.
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8. Moh’s Scale
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9. Hardness scale
A mineral with a greater number can scratch all minerals with a lesser number.
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10. Reread pg 304 with your shoulder partner and answer questions 3&4
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11. Color pg 305 Color describes a mineral’s outside appearance.
Elements that make up a mineral may affect its color
The element copper gives malachite a green color.
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12. Streak Streak is the color of a mineral in its powdered form
To see a mineral’s streak, you rub it on a hard, rough, white surface or black surface. Called a streak plate.
Streak Plate
The powder can be the same as or very different from the mineral’s outside appearance.
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13. Shape The shape of a mineral’s crystals is not always easy to see
Some minerals have a definite shape that is helpful for identification.
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14. Magnetism A few minerals have magnetic properties
Pyrrhyotite and certain varieties of magnetite are strongly magnetic.
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15. Identifying minerals
In order to identify an unknown mineral, scientists first make many observations.
Then, they compare their observations with charts of known minerals.
The chart gives the names and properties of several minerals.
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16. Economic significance
Many common products contain minerals.
Minerals are the source of metals such as iron, copper, and silver.
Many minerals are used in foods, medicines, fertilizers, and building materials.
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17. Lesson 4 Rocks There are three kinds of rocks Igneous Sedimentary
metamorphic

18. Id-ing rocks
By looking at how the minerals in the rock are arranged, it is often possible to determine how the rock was formed

19. Igneous
Rocks that form when melted rock cools and hardens are called igneous rocks.

20. Igneous rocks con’d
Igneous rocks can form deep inside Earth or from lava that hardens on Earth’s surface.

21. Igneous rocks con’d
As hot, liquid rock cools, crystals of minerals form. Melted rock cools slowly results in igneous rocks with large crystals of minerals
Melted rock that cools quickly results in igneous rocks with small crystals.

22. Sedimentary Rocks
Most sedimentary rocks form when layers of materials and rock particles settle on top of each other and then harden.

23. Sedimentary rocks con’d
Minerals from water may act like cement. They hold the particles together.
Sandstone and conglomerate are examples of sedimentary rock.

24. Sandstone
Sandstone can form when layers of sand are buried and put under pressure.
Large, rounded particles that have been pressed together form conglomerate.

25. Metamorphic Rocks
When solid rock is squeezed and heated to very high temperatures, the particles inside the rock can take on different arrangements.
Metamorphic rock is rock formed inside Earth from other rocks under heat and pressure

26. The Rock Cycle
Rocks are constantly being formed and destroyed in a process called the Rock Cycle.
Rocks may be changed from one kind to another in any order or stay the same for millions of years.
See page 311

27. Id-ing rocks
Rocks are made of mixtures of minerals and other materials.
Some rocks contain only one type of mineral.
Others contain many minerals.

28. HighLight IT!!! Quickly!!!! And Quietly Turn to page 309
Get out a highlighter

29. Causes of Erosion pg 315
Materials such as rock particles on Earth move.
Water, wind, and ice can carry particles from one place to another place.
The movement of materials away from a place is called erosion.

30. Causes of Erosion pg 315 Erosion is a destructive process.
Gravity is the main force causing erosion.
In a landslide, gravity is the main force causing erosion.

31. Water Erosion
Moving water causes much of the erosion that shapes Earth’s surface.
Rivers, rain, waves, ocean currents, and glaciers are all forms of moving water.

32. Rivers Gravity causes rivers to flow
As rivers flow downhill, they pick up and carry sediments, such as rock, soil, and sand.
The sediments can erode the riverbeds by grinding against the riverbeds again and again.

33. Rain Rain can loosen sediments from the soil and carry them away.
Rain can cause flooding in low, flat area.
Flooding damages soil, roads, and buildings.