Experiments in Crystal Optics
This activity was peer reviewed prior to publication in the Teaching Mineralogy Workbook.
This teaching activity was originally published in: Brady, J., Mogk, D. W., and Perkins, D., (editors), 1997, "Teaching Mineralogy," a workbook published by the Mineralogical Society of America, 406 pp. All teaching activities in this volume received two external peer reviews from mineralogy faculty focused on content and pedagogy, and a final review by the co-editors to comply with the publication standards of the Mineralogical Society of America.
This activity was selected for the On the Cutting Edge Reviewed Teaching Collection
This activity has received positive reviews in a peer review process involving five review categories. The five categories included in the process are
- Scientific Accuracy
- Alignment of Learning Goals, Activities, and Assessments
- Pedagogic Effectiveness
- Robustness (usability and dependability of all components)
- Completeness of the ActivitySheet web page
For more information about the peer review process itself, please see http://serc.carleton.edu/NAGTWorkshops/review.html.
This page first made public: May 9, 2008
Skills and concepts that students must have mastered
How the activity is situated in the course
Content/concepts goals for this activity
Higher order thinking skills goals for this activity
Other skills goals for this activity
Description of the activity/assignment
Generally, students are comfortable with simple optical terms like reflection and refraction, while it is uncommon that they actually have seen double-refraction and noticed that crystals polarize light. Many have an unnecessarily complicated idea about vibration directions, interference colors, and interference figures; they assume such phenomena always require a microscope to observe. This is not so. Students well trained in thin section microscopy are often surprised that interference figures can be made visible macroscopically.
The purpose of the experiments below is to impart an intuitive understanding of the interaction between light and crystals and, thus, of optical crystallography. This will help to demystify what is seen in the polarizing microscope, and will better prepare the student for the introduction of optical indicatrices as 3-D models to describe the directional dependence of light velocities, and thus refractive indices in anisotropic crystals.
Determining whether students have met the goals
Download teaching materials and tips
- Assignment description, hand outs, and instructor's notes. (Microsoft Word 453kB May9 08)
- Assignment description, hand outs, and instructor's notes. (Acrobat (PDF) 106kB May9 08)
Bretschneider, E. & Scholz, O. (1974) Die Physik in Versuchen - Optik. PHYWE Schriftenreihe. 14. Aufl., Goettingen, 1974.
Dowty, E. ATOMS, Computer Program for Displaying Atomic Structures Macintosh Version 1.2, 1992.
Sears F.W., Zemansky M.W. & Young H.D. College Physics, 7th ed. Reading, Mass., 1991, 1060p.
Zimmermann, H.D. Polarisationsmikroskopi. Copenhagen, 1989, 350p.
Mineralogical Society of America - Join today!