Mineral:  Orthoclase KAlSi3O8

Sample No.:  orthocl.3

XRD Analysis:  Pure orthoclase.

Chemistry:  Microprobe analysis indicated typical orthoclase 
composition but there is a slight heterogeneity of the alkalies.  Soda 
varies from 1.5 to 3.5%, while potash varies from 11 to 14%. 
Average of 14 analyses:

SiO2	64.81
TiO2	0.02
Al2O3	19.11
MnO	0.03
K2O	13.51
Na2O	1.69
FeO	0.02
MgO 	0.04
CaO	0.04
	_____
Total	99.34
