Chapter 7 Lesson 2, "Properties Used to Identify Minerals"

Materials:

• Worksheet: Properties Used to Identify Minerals.
• Resource Kit, Streak plate and mineral samples for students to test.

Objective:

• Students will identify four properties of minerals.
• Students will assess color as a way to identify minerals.
• Students will define luster.
• Students will describe a streak test.
• Students will explain how to test the hardness of a mineral.

Anticipatory Set:* Students will veiw picture of a mineral quartz and be ask to identify its properties. Then students will be shown 11 other pictures of quartz. Then ask why color is not the only property you should look at when determining a mineral's name. Quartz, 1, 2, 3, 4, 5, 6 ,7, 8, 9, 10, 11, 12.

Teacher Input:* Student will be shown a sulfur mineral and asked to identify it. They will most likely know it as sulfur. Tell them that since there are not many yellow minerals they can get away with knowing that one property to give them a good idea of the mineral. However, remind them of the 12 samples of quartz and that geologists use many other properties to identify minerals. Look at gold and pyrite. These are not the same minerals but they appear very similar. Look at gold and pyrite and then show the cartoon Fools gold. Mention how mistakes in mineral identification can be costly. Does anyone know the best test to determine the difference between gold and pyrite? (hardness)

How do we determine hardness? Look at mohs' scale of hardness. Mohs' 1, Mohs' 2, Mohs' 3.

The next property we should look at is luster. What is luster? (different minerals reflect light differently) Here are some examples: shiny (metallic), dull (nonmetallic), pearly, glassy.

Testing Steak- Show the students a streak plate (This is in the resource kit) and use it to identify the color of different streaks. streak (streak plate has a hardness of about a 6)

What do I mean when I say it has a hardness of 6. Recall the earlier discussion. Ask what color streak will pink quartz leave on the plate?

Guided Practice:* Go through the questions on page 161 with the students.

Hand each student a different mineral from the mineral kit. Remind them not to remove the identification number. Show the students this site: http://geology.csupomona.edu/alert/mineral/id1.htm help them use it to identify the mineral they have and the sample mineral.

Independent Practice:* Students will complete the worksheet: Properties Used to Identify Minerals.

Check for Understanding:* Students will complete the quiz, Chapter 7 Lesson 2.

Duration:

30 minutes + 10-15 for Independent Practice (Could be longer if taken for homework).

Alaska Content Standards Addressed in this lesson:

• SCI A-1 Students will understand models describing the nature of molecules, atoms, and sub-atomic particles and the relation of the models to the structure and behavior of matter (Structure of Matter);

• SCI A-15 Students will use science to understand and describe the local environment (Local Knowledge); and: