Week 7: Task #2: Science Lesson

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/)

Mineral Physical Properties Chart
PHYSICAL PROPERTY	Definition*	Testing Method
Cleavage	Breakage of a mineral along planes of weakness in the crystal structure.	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.
Color	Visible light spectrum radiation reflected from a mineral.	Look at the sample and determine its color - white, black, green, clear, etc.
Crystal Form	Geometric shape of a crystal or mineral.	Examine and describe the geometric shape of the mineral - cubic, hexagonal, etc. Not commonly seen in most introductory lab samples.
Fracture	Breakage of a mineral, not along planes of weakness in the crystral structure.	Examine the mineral for areas where the mineral is broken. Describe the breakage as either irregular or conchoidal (has the appearance of broken glass)
Hardness	Resistance to scratching or abrasion.	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.
Luster	Character of the light reflected by a mineral.	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).
Magnetism	Electromagnetic force generated by an object or electrical field.	Use a magnet to determine if the magnet is attracted to the sample.
Streak	Color of the mineral when it is powdered.	Grind a small amount of a mineral into a powder on a porcelain streak plate and determine the color of the powder.

* 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?