Name: Tourmaline (Schorl) NaFe3+2Al6(BO3)3Si6O18(OH)4
Type: Mineral
Class: Silicate
Subclass: Cyclosilicate
Particle Size: Coarse
Sample No.: tourmal_2
Owner: JHU
Wavelength Range: TIR
Origin: Minas Gerais, Brazil via the Hunt and Salisbury Collection#120B (purchased from Ward's Natural Science Establishment)
Collection Date: N/A
Description: The sample was a translucent, blue, single crystal.  It appeared quite pure under the petrographic microscope.(Ring Silicates)Particle size was 75 - 250  Micrometers. Original ASTER Spectral Library name was jhu.nicolet.mineral.silicate.cyclosilicate.coarse.tourma2.spectrum.txt
Mineral:  Tourmaline (Schorl) NaFe3+2Al6(BO3)3Si6O18(OH)4

Sample No.:  tourmal.2

XRD Analysis:  Pure tourmaline.

Chemistry:  Microprobe analysis showed that the sample was 
homogeneous between and within grains.  An average of 10 analyses 
lacks information on boron and water but shows sufficient iron 
present to confirm schorl composition:

SiO2	35.11
Al2O3	34.52
FeO	11.98
MgO	1.02
CaO	0.07
K2O	0.04
Na2O	1.38
TiO2	0.05
MnO	0.27
	_____
Total	*84.44
	*Li, B, and OH not measured.
