Review Questions for Lecture 16:
Earth's Crust; Phyllosilicates, Non-Quad Inosilicates

1. Phyllosilicates are characterized by what linkage of the SiO4 tetrahedra?
    Why does muscovite have Al_2 whereas biotite has Fe_3 in the Y site?

2.  Differentiate among the phyllosilicates: true micas, brittle micas and clay minerals.

3. Describe the T-O vs. T-O-T structures. How can we use the 'c' unit cell dimension to
    distinguish between these two structures?

4. Describe the three different serpentine polymorphs.

5. Why is the term "clay" a confusing term?

6. Describe 'clay' minerals?

7. If you were choosing between building your house on a substrate
of illite or montmorillonite, which would you choose and why?
What does the presence of illite tell you about the geologic environment?

8. What is a non-quad pyroxene?
                       non-quad amphiboles?

9. What are the geologic environments indicated by:

10. What other minerals are associated with:

11. What is a pyroxenoid?

12. What is a biopyribole?