Geology 15                                                                                          Summer 2000

West Valley College                                                                         R. Lopez

Geology of California


Study Questions 3



1)      Define “chemical element”.  What are the eight most abundant elements in the Earth’s crust?



2)      The building blocks of rocks are what?



3)      What is the four part definition of a mineral.



4)      What are the mineral names and chemical compositions of the chemical compounds sodium chloride, silica dioxide, and calcium carbonate.


5)      What are silicate minerals?


6)      What is cubic, rhombohedron, hexagonal, and sheet silicate crystal forms?



7)      What elements are in K-feldspar and plagioclase feldspar (you do not need to know the exact chemical formula).



8)      Plagioclase is a “solid solution”, briefly discuss what that means using plagioclase as an example.



9)      How do amorphous and crystalline materials differ?  Is volcanic glass crystalline?



10)  Cleavage is characterized by three properties, what are they?



11)  How do cleavage and fracture differ?  What is conchoidal fracture?



12)  On Mohs hardness scale, what is the hardness of your fingernail, a knife blade, and quartz.



13)  Your teeth and bones are made of what mineral?



14)  What are the two primary types of luster?



15)  Define specific gravity.



16)  Graphite and diamond are both composed of Carbon (C).  What is the crystallographic name for two minerals composed of the same chemical formula?



17)  Why is graphite sheet-like and soft whereas diamond is so hard?