1. Bell Work 9/15/2017-Get comp book!
Which property describes the reflection of light off the surface of the mineral?
A. Color C. Luster
B. Density D. Hardness
Which property is the LEAST reliable for mineral identification?

2. Identifying Minerals
Comp Book page 12

3. Today’s Goals… Explain the breakage of minerals: fracture and cleavage
Determine the identity of a mineral based on its density, fracture, and/or cleavage

4. Set up foldable…
Color
Luster
Streak
Breakage
Density
Hardness

5. COLOR Most minerals occur in more than one color. Worst property to
identify a mineral
by.

6. LUSTER
Luster refers to how light is reflected from the surface of a mineral.
Metallic (metal), Nonmetallic (glossy), No Luster (dull)

7. Breakage Fracture Cleavage Break irregularly
Break along parallel, flat surfaces

8. Examples of cleavage:

9. Cleavage …cont.
Sheet
Blocky
Prismatic
Rhombohedral
Cubic

10. Examples of Fracture:

11. Cleavage or Fracture?
Cleavage

12. Cleavage or Fracture?
Fracture

13. Cleavage or Fracture?
Cleavage

14. Cleavage or Fracture?
Cleavage

15. Cleavage or Fracture?
Fracture

16. Cleavage or Fracture?
Cleavage

17. With a partner
Observe different pictures and minerals of luster and breakage.
Decide if the breakage is fracture or cleavage and nonmetallic or metallic.
Write your responses on your answer sheet.