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
