Mineral:  Biotite K(Mg,Fe+2)3(Al,Fe+3)Si3O10(OH,F)2

Sample No.: biotite.2

XRD Analysis:  Sample is biotite plus very weak peaks due to another 
component at 9.3 and 5.98 angstroms.

Chemistry:  Microprobe analysis shows average biotite composition.  
Average of six analyses:

SiO2	38.80
Al2O3	11.50
FeO	17.63
MgO	13.54
CaO	0.03
K2O	8.60
Na2O	0.59
TiO2 	2.14
Cr2O3	0.06
	_____
Total	*92.89
*OH and F not measured
