A strange, well developed, lustrous terminated crystal of one of the most rare varieties of tourmaline. At the time, this was found only once in the mid 1900s, and then not again until a few very limited later discoveries, by which time it was recognized as a new species of tourmaline. The color is due to the interaction of Fe3+ and O2-. “Buergerite” was renamed to Fluor-Buergerite by the IMA in 2011 in a bit of confusing nomenclature updating. This very rare silicate crystal is the type material that is F-dominant (Henry et al., 2011). This locality produces the world’s best specimens by far and these robust crystals, from old discoveries, are the best of them. Photo: Jeff Scovil (2013-03-0135) Photoed: The Mineralogical Record, 2013; 88(5): 444: The Mineralogical Record, Mineral Collections of Arizona, 2013; 44(3) (Suppl): 205. Photoed: Rubellite chapter in “Color in Tourmaline”, by Dr. George R. Rossman, 2019, p. 30, (Lithographie: Arvada, Colorado). Illustrated in a nice article and summary of this material in Rocks & MInerals magazine in 2013 (vol. 88 #5, page 444). Featured in the book on thumbnail collecting, Refined Elegance (Mineralogical Record, Nov. 2022) on page 110. We do not have old labels but Alex noted this came from the Richard Bideaux collection.