Name: Biotite K(Mg,Fe+2)3(Al,Fe+3)Si3O10(OH,F)2
Type: Mineral
Class: Silicate
Subclass: Phyllosilicate
Particle Size: Solid
Sample No.: biotite_1
Owner: JHU
Wavelength Range: TIR
Origin: Source Smithsonian NMNH 78303 Sample from Wakefield,Quebec, Canada. 
Collection Date: N/A
Description: Sample consisted of four large (5 cm x 5 cm x 3 cm) pieces of a single hexagonal "book" weighing 15.7 g. A 1 mm sample was dark brown in color, while a thin cleavage flake was tan. Despite the high magnesium content (see ancillary file), cleavage surfaces do not display the coppery glint typical of phlogopite. Sample was pure except for a very few (much less than 1%) opaque inclusions. (Mica Group) Original ASTER Spectral Library name was jhu.nicolet.mineral.silicate.phyllosilicate.solid.biotit1.spectrum.txt
Mineral:  Biotite K(Mg,Fe+2)3(Al,Fe+3)Si3O10(OH,F)2

Sample No.: biotite.1

XRD Analysis:  Pure biotite.

Chemistry:  Microprobe analysis was difficult because of sample 
mounting problems, but the sample seemed to be homogeneous 
within and between grains.  An average of 5 analyses showed 
sufficient magnesium that this might almost be classified as a 
phlogopite:

SiO2	38.21
Al2O3	 15.72
FeO	9.58
MgO	18.72
CaO 	0.13
K2O 	9.24
Na2O	0.20
TiO2	2.16
Cr2O3	0.05
	_____
Total	*94.01
*OH and F not measured
