Objectives for the topic: Petrography

Reading: See syllabus

Images to understand: See syllabus

After completing this topic, the student will be able to:

1. Define polarized light.
2. Describe and sketch a thin section in cross-section.
3. Define: plane-polarized light, cross-polarized light.
4. Explain relief, and its relationship to index of refraction.
5. Explain the distinction between degree of relief and sign of relief.
6. Describe how to determine degree of relief.
7. Describe how to determine sign of relief.
8. Define pleochroism.
9. Sketch cleavage observed in thin section.
10. Interpret textbook diagrams showing cleavage, growth faces, etc.
11. Determine interference color.
12. Describe the way to tell if a mineral is isotropic.
13. Measure birefringence from a set of randomly oriented grains of a mineral at standard thickness.
14. Given two of the features (thickness, birefringence, interference color), use the Interference Color Chart to determine the third.
15. Given two of the features (thickness, birefringence, interference color), use the relationship: thickness x birefringence = int. color to determine the third.