Chapters Covered by Exam #3:

In Nesse, Introduction to Mineralogy
• Chapter 6 - Physical Properties are the Meat and Potatoes of Mineral ID - know this stuff well.
• Chapter 7 - Optical Properties - I expect the exam to focus on both the basics of optical theory (polarized light, refractive indices, birefringence) and practical application to identifying the common ingeous rock forming minerals. Skip the sections on accessory plates, interference figures, optic sign, 2V, and Reflected Light Optics
• Chapter 8 - X-Ray Crystallography - know how X-rays are generated, the configuration of an XRD, and the use of the Bragg Law
• Chapter 9 - Chemical Analysis - know the various tools used to obtain geochemical data as well as their strengths and weaknesses. Understand the recalculating a chemical analysis into a mineral's chemical formula.
• Chapter 10 - Strategies for Study - a couple more analytical prep techniques here to know. Mineral associations are important (See Appendix C for more detail) and beware of pitfalls.

Some examples of essay-type questions:

• Consider the polymorphs graphite and diamond. Identify the following physical properties for each mineral and explain the crystal chemical origins of each: color, luster, streak, specific gravity, electrical conductivity, and hardness.
• Are chemical or structural properties of a mineral more important in determinging its: a) specific gravity, b) hardness, c) cleavage, d) color, and e) magnetism? Explain.
• Identify and describe four different color causing mechanisms. Give an example of a mineral that typifies each.
• Define: brittle, malleable, ductile, sectile, elastic, and flexible. What is the difference between tenacity, cleavage, fracture, and parting?
• List the minerals of Mohs Hardness Scale from weakest to hardest. What is the origin of the differences in hardness between the minerals at the opposite ends of this scale?
• How is polarized light produced? Why is it useful for studying minerals? Diagram (schematically) the important parts of a petrographic microscope.
• Which crystal systems display anisotropic, uniaxial, and biaxial optical behavior? Define the "index of refraction". How is this related to Snell's law?
• What optical properties are observable under plane polarized light and which are observable under cross polarized light? Explain how one recognizes pleochroism and give an example of a mineral that displays it. What is parallel extinction? inclined extinction? symmertical extinction?
• What is the origin of interference colors? How is birefringence determined? How is the Becke line use to determine relief?
• Diagram an X-ray diffractometer. How are copper K_α X-rays produced? What is the Bragg Equation and how is it used to determine lattice spacings in minerals?
• Identify four different methods of geochemical analysis. What are the strengths and weaknesses of each method?
• How are chemical analyses of minerals used to determine precise stoichometric chemical formulas? Give a real world example of why one would care about the chemical composition of a garnet anyhow.
• You are given an unknown mineral specimen and asked to identify it. Devise an analytical plan (unlimited budget). What methods will you employ? What will each tell you?

Some examples of multiple choice-type questions: See the quizzes.