Name: Orthoclase KAlSi3O8
Type: Mineral
Class: Silicate
Subclass: Tectosilicate
Particle Size: Solid
Sample No.: orthocl_3
Owner: JHU
Wavelength Range: TIR
Origin: Harris Farm Mica Mine, near Oliver, Goochland Co., Virginiavia the Smithsonian (sample no. NMNH 113188)
Collection Date: N/A
Description: The hand sample is a single 11.97 g fragment of a single crystal.  It is twinned, translucent, light beige in color and appears very pure. Under the microscope, the sample is slightly altered to sericite, otherwise pure. Sample was parallel to 001.(Framework Silicates); (Feldspar Group) Original ASTER Spectral Library name was jhu.nicolet.mineral.silicate.tectosilicate.solid.orthoc3.spectrum.txt
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
