1. Università degli Studi di Milano, Dipartimento di Scienze della Terra, Via Botticelli 23, I-20133 Milano, Italy
2. † Special collection papers can be found online at http://www.minsocam.org/MSA/AmMin/special-collections.html.
3. University of Vienna, Department of Mineralogy and Crystallography, A-1090 Wien, Austria
4. Gemological Institute of America, Carlsbad, California 92008, U.S.A.