CHAPTER 10 Minerals and Rocks By Jamie Desrochers

CHAPTER 10CHAPTER 10

Minerals and RocksMinerals and RocksBy Jamie DesrochersBy Jamie Desrochers

Lesson 1 What are minerals?Lesson 1 What are minerals?ObjectivesObjectives

• Explain what a mineral is.

• Name some common minerals.

• Identify four properties of minerals.

• Explain how to test the streak and hardness of a mineral.

(Marshall et al, 2001)

DefinitionDefinition(Please enter into your notebook)(Please enter into your notebook)

• Mineral -Element or compound found in the Earth’s crust (Marshall et al, 2001)

MineralsMinerals

• They are solids.• They are formed naturally.• They have the same chemical makeup throughout.• They have a definite arrangement of atoms.(Marshall et al, 2001)

Common MineralsCommon Minerals

• There are 3,000 different minerals• Most common minerals are

– Quartz– Feldspar– Mica– Calcite– Gypsum– Halite(Marshall et al, 2001)

Did you know?Did you know?

• Quartz vibrates at a precise, constant speed when electricity passes through it. Watches use tiny bits of vibrating quartz to keep time. (Marshall et al, 2001)

(The Amethysts, 2003)

Properties of MineralsProperties of Minerals

• Four properties can be used to identify minerals.– Color– Luster– Streak– Hardness


ColorColor

• Some minerals have unique color

-Sulfur is usually bright yellow

• Quartz may be clear, pink, black, white, or purple

• Color is only one clue to a mineral’s identity



• Luster-The way a mineral reflects light(Marshall et al, 2001)

LusterLuster

• There are two kinds of luster– Metallic – Nonmetallic

• Glassy• Pearly (Marshall et al, 2001)

Common Luster ChartCommon Luster ChartMinerals Luster

Gold Metallic

Quartz Glassy

Calcite Glassy

Halite Glassy

Talc Pearly

Garnet Glassy

Silver Metallic

Pyrite Metallic(Marshall et al, 2001)


• Streak -Color of the mark a mineral makes on a white tile (Marshall et al,

2001)

(Yahoo image, 2005)


• Hardness -The ability of a mineral to resist being scratched (Marshall et al, 2001)

StreakStreak

• A streak test helps to identify a mineral

• A streak may be different then the minerals color

• Some minerals are so hard that they do not leave a streak


HardnessHardness

• Geologist use a hardness scale from 1 to 10.

• The scale is called the Mohs scale.

• The higher the number the harder the mineral.

• A mineral with a higher number will scratch a lower numbered mineral.

• (Marshall et al, 2001)

Mohs Scale of HardnessMohs Scale of Hardness

Mineral Hardness Quick TestTalc 1 Easily scratch by fingernail

Gypsum 2 Scratch by fingernail

Calcite 3 Barley scratched by copper penny

Fluorite 4 Easily scratched by steel

Apatite 5 Scratched by steel

Feldspar 6 Scratches glass easily

Quartz 7 Scratches both glass and steel easily

Topaz 8 Scratches quartz

Corundum 9 No simple test

Diamond 10 No simple test


Self-CheckSelf-Check(Please answer in your notebook)(Please answer in your notebook)

1. What is a mineral?2. Name two common minerals?3. Why can’t color alone be used to identify

minerals?4. Why is a streak test helpful in identifying

minerals?5. The hardness of quartz is 7. The

hardness of topaz is 8. Will quartz scratch topaz. Explain.

Check Your AnswersCheck Your Answers

1. A naturally occurring solid, not made of living things, with a definite atomic pattern and the same chemical composition throughout.

2. Answer may vary but may include: gold, quartz, diamonds, carbon, feldspar, mica

3. Most minerals are found in more than one color, and many minerals are similar in color.

4. A mineral streak may be different then the mineral’s color.

5. No, on the Mohs hardness scale, a mineral with a higher number is harder than a mineral with a lower number. The softer mineral. Quartz will not scratch the harder mineral topaz.

Lesson 2 What are rocks?Lesson 2 What are rocks?ObjectivesObjectives

• Explain what rocks are.

• Name and describe three main types of rocks.

• Describe the rock cycle. (Marshall et al, 2001)


• Rock -Natural solid material made of one or more minerals. (Marshall et al, 2001)

•(Yahoo image, 2005)

Minerals make up rocksMinerals make up rocks

• Only 20% of minerals make up 95% of rocks.

• Scientists who study rocks are interested in which minerals make them up and how the rocks are formed.

• The information helps locate valuable resources. (Marshall et al, 2001)

DefinitionsDefinitions(Please enter into your notebook)(Please enter into your notebook)

• Igneous rock -Rock formed from melted minerals the have cooled and hardened.

• Magma -Hot liquid rock inside the Earth.• Metamorphic rock -Rock that had been changed

by intense heat, pressure, and chemical reactions.

• Sedimentary rock -Rock formed from pieces of other rock and organic matter that was pressed and cemented together. (Marshall et al, 2001)

Three Types of RocksThree Types of Rocks

• Rocks are classified by how they are formed– Igneous rocks are formed from magma inside

the Earth– Metamorphic rocks are formed from heat and

pressure– Sedimentary rocks are formed by bits and

pieces cemented together. (Marshall et al, 2001)

Rock ImagesRock Images

• Top left-sedimentary rock• Top middle-metamorphic rock• Top right-Igneous rock• (Yahoo image, 2005)

Common Rock ChartCommon Rock Chart

Igneous Sedimentary Metamorphic

Basalt Chalk Amphibolite

Diorite Dolomite Gneiss

Granite Flint Marble

Obsidian Limestone Metaquartzite

Pumice Sandstone Schist

Rhyolite Shale slate



• Rock Cycle – Series of changes through which one kind of rock becomes another kind of rock. (Marshall et al, 2001)

The Rock CycleThe Rock Cycle

• Magma rises, cools, and hardens into igneous rock.

• It rises to the surface breaks apart, forming sediment.

• Sediment is carried to the ocean by rivers were it builds up and becomes sedimentary rock.

• Heat and pressure change it into metamorphic rock.

• The rock cycle can have many other paths.

(The Rock Cycle, 1997)

Self-CheckSelf-Check(Please answer in your notebook)(Please answer in your notebook)

1. What is a rock?

2. What are the three main types of rocks?

3. Which type of rock is granite?

4. How do metamorphic rocks form?

5. Explain the rock cycle.

Check Your WorkCheck Your Work

1. A natural solid material made of one or more minerals

2. Igneous, sedimentary, and metamorphic rocks

3. Igneous

4. Heat, pressure, and hot fluids change the appearance and texture of preexisting rock to form metamorphic rocks.

5. A series of changes that rocks undergo as they change into other rocks.

QuizQuiz(Please answer in your notebook)(Please answer in your notebook)

• What are four features that all minerals have in common?

• What is a rock?• How do scientist use information about

rocks?• Name the three types of rock and describe

how each type if formed?• Describe how the “quick test” is used to

estimate a mineral’s hardness.

FYIFYIFor more information about rocks and minerals please

check out the following websites.

• The Mineral Gallery http://www.fi.edu/tfi/units/rocks/rocks.html

• Rocks and Mineral Slide Showhttp://volcano.und.nodak.edu/.../

vwlessons/lessons/Slideshow/Slideinex.html

• Rock and Mineral Web Questhttp://cte.jhu.edu/techacademy/fellows/brannon/webquest/kmbindex.html

• Rock and Mineral Linkshttp://edtech.kennesaw.edu/web/rocks.html

ReferencesReferences

• Center for Educational Technology, (1997). The rock cycle. retrieved Jan. 22, 2005, from Earth's Cycles Web site: http://ww.cotf.edu/ete/modules/msese/earthsysflr/rock.html

• Marshall, R., Jacobs, D., Rosskopf, A., & LaRue, C. (2001). General science. Circle Pines, MN: American Guidance Service.

• Yahoo image. (2005). retrieved Jan. 22, 2005, from Rock imagin Web site: http://images.search.yahoo.com/search/images

• The Amethyst. (2003). Retrieved February 8, 2005) from Amethyst web site: http://

mineral.galleries.com/minerals/silicate/quartz/quart

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CHAPTER 10 Minerals and Rocks By Jamie Desrochers