8. Give examples of organically derived rocks.
9. What kinds of rocks are embraced by the Metamorphic class?
10. What are igneous rocks?
12. What is the mineralogical composition of granite?
13. What is meant by a mineral?
14. Name five minerals which do not contain oxygen. Where does fluor-spar occur? What is the element that enters most largely into the composition of the earth's crust?
15. Name the forms under which the mineral quartz occurs. Name some of the oxides of iron. What is iron pyrites?
16. Name two sulphates. Name two carbonates. Name some of the silicates. In what kinds of rock is augite found? Where does it never occur? In what kinds of rock does hornblende usually occur? Mention three species of felspar. What is one of the most distinguishing characteristics of mica? Name three silicates of magnesia. Mention some of their distinguishing peculiarities. Where do zeolites commonly occur?
17. What is a quartzose conglomerate? What is a calcareous conglomerate?
18. What is grit? What is freestone? To what are the various colours of sandstone due? What is shale?