ABSTRACT
Single octahedral crystal of α-cristobalite was found in 1941 by a young soldier, Bennett Frank Buie in the Ellora Caves located in the northeast corner of Hyderabad State, India. e crystals were in a cool cave associated with the zeolite, mordenite. Van Valkenburg did the laboratory analysis while Buie was on active duty with the U.S. Army. Buie gave a specimen to Harvard University. Years later Carl Francis of the Harvard University Mineralogical Museum allowed Robert T. Downs to shake out the box the sample was stored in. at was where he got the single crystal of α-cristobalite that was used in the study for this chapter. (Van Valkenburg and Buie, 1945. Photograph courtesy of the RRUFF project.)
CONTENTS Chapter Objectives 450 12.1 Introduction 451
12.1.1 Special Topic: Polyhedrons 451 12.1.2 Special Topic: Enantiomorphic Pairs of Space Groups 452
• Study the crystallographic properties of α-cristobalite, space group #92, P41212, as a representative of the tetragonal crystal system.
