Review Questions for Lecture 19:  Earth's Crust;
    Carbonates

1. Describe the anionic complex that characterizes this non-silicate group?
    Why is it called a 'radical'? What is the bond strength within/outside
    of the group.

2.  Why does CaCO3 form two polymorphs?
        These polymorphs also define groups. Whatis the main difference between these
         groups.
         Is there solid solution between the groups? why/why not?

3. Describe distinguishing features of the rhombohedral carbonates.

4. What are the geologic environments/conditions, e.g. P, T, or composition, indicated by:
      aragonite?
       cerrusite?
       siderite?
       malachite?
       smithsonite?

5. Compare and contrast crystal forms, properties of
    calcite and dolomite

6. What geologic environments form carbonates?