Name: Topaz Al2SiO4(F,OH)2
Type: Mineral
Class: Silicate
Subclass: Nesosilicate
Particle Size: Coarse
Sample No.: topaz_1
Owner: JHU
Wavelength Range: TIR
Origin: Rhondonia, Brazil via Don Hoover, USGS
Collection Date: N/A
Description: The sample was a 1 cm x 1 cm x 1 cm fragment of a single crystal.  It was colorless and appeared free of fluid inclusions under the microscope (however, the presence of a CO2 band at 4.3 micrometers in the infrared reflectance spectra of particulate samples shows that fluid inclusions are present). Particle size was 75 - 250  Micrometers.(Isolated tetrahedra) Original ASTER Spectral Library name was jhu.nicolet.mineral.silicate.nesosilicate.coarse.topaz1.spectrum.txt
Mineral:  Topaz Al2SiO4(F,OH)2

Sample No.:  topaz.1

XRD Analysis:  Pure topaz.

Chemistry:   Microprobe analysis by Lou Walter and volatile analysis 
by C. S. Papp, J. D. Sharkey, and K. J. Curry and XRF analysis of the 
non-volatiles by J. Taggare, A. Bartel, , USGS Branch of Analytical 
Chemistry, Denver.  Ten microprobe analyses indicate homogeneity 
within and among grains, and the composition agrees with that of 
topaz.  Average of 10 analyses:

SiO2	36.50
Al2O3	62.50
FeO	<0.05
MgO	0.15
CaO	<0.02
K2O	<0.02
Na2O	<0.17
TiO2	<0.02
MnO	<0.02
P2O5	<0.06
H2O	0.15
CO2	<0.01
F	0.10
	_____
Total	99.77
