Download midterm review 2006

Earth Materials Midterm Exam Review Outline
Spring 2006
Review session 8:30 pm Wednesday night room 219 (lecture room) – bring specific
questions, problems (ex. “Can you explain Pauling’s rules?” is not a specific question,
“How can I determine if a molecular subunit is anisodesmic, mesodesmic, or
isodesmic?”)
All Materials may be found in either the notes or the material covered in the book (and
usually both).
The following is an outline of the material which you are expected to be responsible for
on the mid-term exam next week (pertinent sections in text bracketed)
1. General chemistry of Earth Materials (Chapter 1):
a. Distribution of elements in the universe and on earth
b. Types of bonds – an understanding in particular of ionic and covalent bonding
in common minerals as well as other types of bonds
2. Pauling’s Rules (Chapter 13)
a. Should know first 2 inside and out (radius ratio and electrostatic valency
principle) to determine coordination numbers, bond strength
b. Know difference between isodesmic, anisodesmic, and mesodesmic subunits,
as well as describe how they are important in bonding and silica
polymerization
3. Know the 7 ways in which silica tetrahedral polymerize, forming the major divisions
of silicate minerals (Chapter 13 page 287-290)
4. Mineral formulas (Chapter 1, page 21-22)
a. Be able to read chemical formulas
b. use binary and ternary compositional diagrams
c. Be able to normalize a simple chemical formula
5. Know what a polymorph is, be able to discuss why they form
6. Mineral Growth – be able to discuss different ways minerals form and get bigger…
(Chapter 2)
7. Be able to discuss different kinds of defects, dislocations, imperfections (like
twinning, zoning) (Chapter 2)
8. Be able to discuss chemical fingerprints – chemical makeup, isotopes
9. Symmetry elements – know the different operators and have some understanding that
they combine to define point groups (Chapter 9)
10. Know the 6 major crystal systems very well!! (Chapter 10)
11. Know how crystal morphology (form) is related to a crystal’s internal structure
12. Miller indices (Chapter 11, page 242-247)
13. Crystallography – be able to define a lattice, unit cell (Chapter 10)
a. Know differences between the 14 Bravais lattices (unit cell types – primitive,
body, face, end-centered)
b. Know how space groups are defined  symmetry point groups, Bravais
lattices, translations
14. Light absorption – you should have a good working knowledge of the
electromagnetic spectrum and basic properties (especially wave forms), wave-particle
duality. (Chapter 4)
a. Color – be well-versed in different ways in which color is developed in
minerals – be able to bring together mineral chemistry/ structure with light
interaction!
b. Luster, diaphaneity – be able to define in terms of light interaction
c. You should have a general understanding of luminescence (difference
between fluorescence and phospholuminescence)
15. Mineral physical properties – have a working knowledge of hardness, density,
magnetism (know types!) and acid reaction  how does all of it relate to mineral
chemistry/ structure (Chapter 3)
16. interaction of electrons ‘shot’ at a mineral  know how electrons may interact and
reflect as well as transmit through minerals and what some of the information this can
provide using SEM, TEM and related detectors
17. Spectroscopic methods – use your understanding of the interaction of light with
minerals to describe the different analytical methods to analyze minerals. For
instance, if I was interested in how to distinguish different clays by investigating the
prescence of OH groups, what tool(s) could I use?  IR spectroscopy, which looks at
the vibration of the O-H bond.
18. X-rays – Be able to describe how X-rays are generated and ways they interact with
minerals (Chapter 12)
19. Interference – you should understand constructive and destructive interference as
applied to any form of electromagnetic radiation!
20. Diffraction – be able to describe diffraction, relationship to spacing of atoms in planes
(defined through crystallography) (Chapter 12)
21. Bragg’s Law – you should understand this very well, be able to use it to generate an
XRD pattern, describe how it works with different sources of radiation, and what kind
of information we can get from X-ray diffraction experiments utilizing Bragg’s Law
(Chapter 12)
22. Optical microscopy (Chapter 4, better description in lab book)
a. How polarizers work in a petrographic microscope
b. Be able to describe how color, relief, pleochroism develop in plane polarized
light
c. Be able to describe light reorientation by minerals under cross polars
d. Recognize how internal order affects optical properties  how are the 6 major
crystal classes divided in terms of optical properties, how can you use optical
microscopy to tell between certain classes?
e. Be able to describe basic principles of refraction, ordinary vs. extraordinary
rays, and how this relates to extinction and birefringence
f. Describe basics of conoscopic projections in microscopy (Bertrand lense),
differences between isometric, uniaxial, biaxial minerals