Name: Topaz Al2SiO4(F,OH)2
Type: Mineral
Class: Silicate
Subclass: Nesosilicate
Particle Size: Coarse
Sample No.: topaz_4
Owner: JHU
Wavelength Range: TIR
Origin: Wsakos, Namibia via Don Hoover, USGS
Collection Date: N/A
Description: The sample consisted of one small colorless fragment less than a centimeter across.  Petrographically the sample appeared pure and clean but contains obvious fluid inclusions. Particle size was 75 - 250  Micrometers.(Isolated tetrahedra) Original ASTER Spectral Library name was jhu.nicolet.mineral.silicate.nesosilicate.coarse.topaz4.spectrum.txt
Mineral:  Topaz Al2SiO4(F,OH)2

Sample No.:  topaz.4

XRD Analysis:  Pure topaz.

Chemistry:  Microprobe analysis by Lou Walter and volatile analysis 
by C. S. Papp, J. D. Sharkey, and K. J. Curry, USGS Branch of Analytical 
Chemistry, Denver.  Ten microprobe analyses indicate homogeneity 
within and between grains.  The composition agrees with that of a 
topaz:

SiO2	36.4
Al2O3	62.2
FeO	<0.04
MgO	0.12
CaO	<0.02
K2O	<0.02
Na2O	<0.17
TiO2	<0.02
MnO	<0.02
P2O5	<0.06
H2O	0.30
CO2	<0.01
F	0.47
	_____
Total	99.85

SOLID SAMPLE SPECTRUM MISSING
