Calcite Crystallography

In this video we examine a calcite rhombohedron and identify symmetry elements in order to orient the calcite rhombohedron crystallographically. We then examine some of the optical properties of a calcite rhombohedron with windows cut to allow viewing along the c crystallographic axis. By changing the orientation of the calcite we can show how light behaves differently when traveling through the calcite crystal in various directions. This means that calcite is anisotropic with respect to light.
The calcite rhombohedrons are viewed in normal everyday light (no plane polarized light here!)
My go to references for the properties of calcite are:
Klein, C. and Dutrow, B. (2007) The 23rd Edition of the Manual of Mineral Science. Hoboken, New Jersey: John Wiley and Sons.
Philpotts, A.R. (2003) Petrography of Igneous and Metamorphic Rocks. Long Grove, Illinois: Waveland Press.
A deeper dive into calcite can be found in the article "Double Trouble: Navigating Birefringence" by Elise A. Skalwold and William A. Bassett
Special thanks to George York for asking about calcite orientation!

[@angushammond1191]

Great vid thank you