Buergerite

Infobox mineral
name = Buergerite
category = Cyclosilicate mineral
formula = NaFe³⁺₃Al₆(BO₃)₃Si₆O₁₈(O,F,OH)₄
color = Bronze, dark brown, black
system = Trigonal - ditrigonal pyramidal (3m)
cleavage = Distinct prismatic
mohs = 7
refractive = nω = 1.735 nε = 1.655
opticalprop = Uniaxial (-)
birefringence = δ = 0.080
streak = yellowish brown
gravity = 3.31
diaphaneity = Translucent

Buergerite is a mineral species belonging to the tourmaline group. It was first described for an occurrence in rhyolitic cavities near Mexquitic, San Luis Potosi, Mexico. It was approved as a mineral in 1966 by the IMA and named in honor of Martin J. Buerger (1903-1986) Professor of Mineralogy at the Massachusetts Institute of Technology. It has also been reported from Minas Gerais, Brazil, and the Central Bohemia Region of the Czech Republic. [ [http://rruff.geo.arizona.edu/doclib/hom/buergerite.pdf Handbook of Mineralogy] ] [ [http://www.mindat.org/min-818.html Mindat] ] [ [http://www.webmineral.com/data/Buergerite.shtml Webmineral data] ]

References