Download Rocks and Minerals

CHAPTER 10
Minerals and Rocks
By Jamie Desrochers
Lesson 1 What are minerals?
Objectives
•
•
•
•
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)
Definition
(Please enter into your notebook)
• Mineral -Element or compound found in
the Earth’s crust (Marshall et al, 2001)
Minerals
•
•
•
•
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 Minerals
• There are 3,000 different minerals
• Most common minerals are
– Quartz
– Feldspar
– Mica
– Calcite
– Gypsum
– Halite
(Marshall et al, 2001)
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 Minerals
• Four properties can be used to identify
minerals.
– Color
– Luster
– Streak
– Hardness
(Marshall et al, 2001)
Color
• 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
(Marshall et al, 2001)
Definition
(Please enter into your notebook)
• Luster-The way a mineral reflects light
(Marshall et al, 2001)
Luster
• There are two kinds of luster
– Metallic
– Nonmetallic
• Glassy
• Pearly (Marshall et al, 2001)
Common Luster Chart
Minerals
Gold
Quartz
Calcite
Halite
Talc
Garnet
Silver
Pyrite
Luster
Metallic
Glassy
Glassy
Glassy
Pearly
Glassy
Metallic
Metallic
(Marshall et al, 2001)
Definition
(Please enter into your notebook)
• Streak -Color of the
mark a mineral makes
on a white tile (Marshall et al,
2001)
(Yahoo image, 2005)
Definition
(Please enter into your notebook)
• Hardness -The ability of a mineral to resist
being scratched (Marshall et al, 2001)
Streak
• 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
(Marshall et al, 2001)
Hardness
• 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 Hardness
Mineral
Hardness
Quick Test
Talc
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
(Marshall et al, 2001)
Self-Check
(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 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?
Objectives
• Explain what rocks are.
• Name and describe three main types of
rocks.
• Describe the rock cycle. (Marshall et al, 2001)
Definition
(Please enter into your notebook)
• Rock -Natural solid
material made of one
or more minerals.
(Marshall et al, 2001)
•(Yahoo image, 2005)
Minerals 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)
Definitions
(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 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 Images
• Top left-sedimentary rock
• Top middle-metamorphic rock
• Top right-Igneous rock
•
(Yahoo image, 2005)
Common Rock Chart
Igneous
Sedimentary
Metamorphic
Basalt
Chalk
Amphibolite
Diorite
Dolomite
Gneiss
Granite
Flint
Marble
Obsidian
Limestone
Metaquartzite
Pumice
Sandstone
Schist
Rhyolite
Shale
slate
(Marshall et al, 2001)
Definition
(Please enter into your notebook)
• Rock Cycle – Series of changes through
which one kind of rock becomes another
kind of rock. (Marshall et al, 2001)
The 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-Check
(Please answer in your notebook)
1.
2.
3.
4.
5.
What is a rock?
What are the three main types of rocks?
Which type of rock is granite?
How do metamorphic rocks form?
Explain the rock cycle.
Check 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.
Quiz
(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.
FYI
For 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 Show
http://volcano.und.nodak.edu/.../vwlessons/lessons/Slideshow/Slideinex.html
• Rock and Mineral Web Quest
http://cte.jhu.edu/techacademy/fellows/brannon/webquest/kmbindex.html
• Rock and Mineral Links
http://edtech.kennesaw.edu/web/rocks.html
References
• 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