Science Lesson
Lesson Topic: Identifying Minerals
Grade: Earth Science Grade 9
Learning Objectives:
By the end of this
lesson, students will be able to . . .
1.
Test minerals using different methods provided
and explained.
2.
Identify accurately different minerals given in
lab.
3.
Discuss different features of tested minerals.
Common Core Skills:
1.
Use a flowchart to identify rocks and minerals.
2.
Conduct a series of tests to identify rocks and
minerals.
Standards:
3.1. Students will understand and apply
scientific concepts, principles and theories pertaining to the physical setting
and living environment and recognize the historical development of ideas in
science.
3.1a. Minerals have physical properties
determined by their chemical composition and crystal structure. Minerals can be identified by well-defined
physical and chemical properties such as cleavage, fracture, color, density,
hardness, streak, luster, crystal shape & reaction with acid.
Vocabulary:
I found this chart at the link listed below. This would be
explained as a whole class, each piece of identifying evidence that will
eventually lead them through testing each mineral for identifying them. We would go over the definition of each of
the physical properties listed in the chart. I did alter the chart to remove
any advanced testing.
Minerals: naturally occurring, inorganic solid with a
definite chemical composition and a regular, internal crystalline structure. (http://facweb.bhc.edu/academics/science/harwoodr/geol101/labs/minerals/)
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Mineral Physical Properties Chart
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PHYSICAL
PROPERTY |
Definition*
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Testing Method
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Cleavage
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Breakage
of a mineral along planes of weakness in the crystal structure.
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Examine
the mineral for areas where the mineral is broken. Look for areas where the
light reflects from planar surfaces. This can be easily confused with a
crystal face and is the most difficult properties for students to master.
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Color
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Visible
light spectrum radiation reflected from a mineral.
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Look
at the sample and determine its color - white, black, green, clear, etc.
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Crystal
Form
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Geometric
shape of a crystal or mineral.
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Examine
and describe the geometric shape of the mineral - cubic, hexagonal, etc. Not
commonly seen in most introductory lab samples.
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Fracture
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Breakage
of a mineral, not along planes of weakness in the crystral structure.
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Examine
the mineral for areas where the mineral is broken. Describe the breakage as
either irregular or conchoidal (has the appearance of broken glass)
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Hardness
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Resistance
to scratching or abrasion.
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Use
minerals of known hardness from the Mohs Hardness Kits. Scratch the unknown
mineral with a known hardness to determine which mineral is harder. Continue
doing this with harder or softer minerals from the kit until the hardness is
determined.
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Luster
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Character
of the light reflected by a mineral.
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Look
at the sample to determine if the mineral is metallic in appearance (looks
like a chunk of metal) or non-metallic (doesn't look like a chunk of metal).
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Magnetism
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Electromagnetic
force generated by an object or electrical field.
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Use
a magnet to determine if the magnet is attracted to the sample.
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Streak
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Color
of the mineral when it is powdered.
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Grind
a small amount of a mineral into a powder on a porcelain streak plate and
determine the color of the powder.
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* Definitions simplified or modified from Bates,
R.L. and J.A. Jackson (eds.), 1987, Glossary of Geology. American Geological
Institute, Alexandria, VA, 788 p.
Materials:
-pen, chart,
graphic organizer, streak plate, magnet, Mohs Hardness Kit, magnifying glass.
Do
Now/Motivation:
The desks
will be arranged in groups of 4. Students will be asked to line up in the front
of the class and count off. They will be asked to be seated in given
groups. When they sit, they will notice
the different minerals in a box, as well as the different tools. Each of the testing tools will be
explained. The minerals will be
numbered. I will then hand out a graphic
organizer. Along the left side will be
each of the different physical properties we have discussed. Across the top of the page will be numbers
corresponding to each of their minerals. They will be told to conduct each of
the tests listed on each of the minerals given in the boxes. They will work together to identify each of
the minerals.
The students
will be asked to fill out the chart as a group and at the end they will compare
as a whole class. We will discuss which attributes led them to their
conclusions. Which tests were most
difficult to use to identify the minerals? And how some groups identified
wrongly, what they misunderstood?