Chapter 7 Lesson 3, "Other Physical Properties of Minerals."
Anticipatory Set:* Mention the last properties we talked about, Color, luster, streak, hardness. Using just those four characteristics can you identify all minerals? Tell the students there are many other properties that can help us identify different minerals. Show them these examples:
Get out your samples of quartz (26) and mica (25) Show the students slides of each and have them compare them. what are some of the differences between them? What causes different minerals to have different shapes and break apart differently? (the arrangement of atoms)
Teacher Input:*Introduce the students to the idea of Crystal Shape. The atoms of each type of mineral or put together in a specific order. NaCl. The shape of the crystal depends on that arrangement. Compare salt and quartz crystals. Each has the same color and luster but through a magnifying glass salt is cubular but quartz crystals have six long sides.
The Pattern that a mineral breaks is also distinctive and depends on the structure of atoms. This pattern is known as what???? Define Cleavage and fracture. Show the students several mineral samples and ask if it is a fracture break or a cleavage break? 1, 2, 3, 4, 5, 6.
If you found a piece of sponge, a small ball of paper, a rubber ball all about the same size as your quartz sample, have the students put them in order of increasing density. When we talk about density of minerals we use the term, Specific Gravity. What is specific gravity? Show the formula for specific gravity and then use some different minerals to determine specific gravity. Students will do this in the Friday lab activity.
Guided Practice:* Go through some of the properties of minerals in the table of this resource file. Also on Page 166 of the text. Explain some of the differences.
Go through the questions on Page 167 with the students.
Independent Practice:* Students will complete the worksheet, "Other Physical Properties of Minerals"
Check for Understanding:* Students will take a quiz on Chapter 7 Lesson 3, "Minerals"
30 minutes + 10-15 for Independent Practice (Could be longer if taken for homework).
Alaska Content Standards Addressed in this lesson: