Review of Minerals:

There are 14 minerals to identify during the next two lab periods. First you should answer questions 1 to 17 below, which are designed to help you get started with your mineral identification. The ultimate goal of this fill is for you to as well complete Data Table 1.3 on pg. 13 and in the process of filling out this table you should learn how to identify some of the most fundamental minerals that exist in nature.

Luster:

1. How many of your minerals have metallic luster? Have non-metallic luster?

2. What specimen while appearing non-metallic by definition has a metallic luster?

LOOK AT LECTURE NOTES

Hardness:

3. An unknown mineral is scratched by a piece of quartz and, in turn, scratches a piece of calcite. What is its hardness or possible range of hardness?

4. Which of your minerals is harder than glass?

Color:

5. Why is color a poor criterion to use (in most cases) for mineral identification?

6. Name two of the mineral specimens in your box that can exhibit different colors. List these minerals and the colors that they can exhibit!

Streak Color:

7. What is the streak color of your metallic luster minerals. Again list your metallic

lustered minerals and the streak colors they exhibit!

8. Corundum is 9 on Mohs hardness scale. Comment on the possible reasons why corundum does not leave a streak powder on the streak plate.

AGAIN LOOK AT LECTURE NOTES [Think about the hardness of the streak plate vs. corundum]

Crystal Form:

9. Quartz can exhibit nice crystal form. However, not all quartz forms large crystals. Discuss!

10. What is the difference between cleavage and crystal form?

AGAIN LOOK AT LECTURE NOTES

Cleavage and Fracture:

11. Of your mineral specimens indicate the mineral that exhibits one good direction of cleavage. And, the specimen that has 3 directions of cleavage.

12. There are several minerals that have 2 cleavage directions and a third fracture surface. In general, how can you tell the difference between a cleavage and fracture surface.

13. What is the difference between the number planes of cleavage and the number of directions of cleavage a mineral exhibits.

Specific Gravity:

14. Which mineral specimen have relatively high specific gravities? What type of luster do these mineral possess.

Other Properties:

15. Which mineral in your box will react with dilute HCl acid?

16. Which mineral in your box has a distinctive “feel.” Describe this feel!

17. Which mineral specimen smells bad particularly if you make a powder out of it?

Complete Table 1.3 in your lab book using the keys on pgs.14 to 16 as an aid to facilitate your identification.