Name: Cordierite Mg2Al4Si5O18
Type: Mineral
Class: Silicate
Subclass: Cyclosilicate
Particle Size: Solid
Sample No.: cordier_2
Owner: JHU
Wavelength Range: TIR
Origin: Sample from Orijarvi, Finland via the Smithsonian  (sampleno. NMNH 78228). 
Collection Date: N/A
Description: The sample consists of three pieces, each about 2 cm x 4 cm x 1 cm.  There are some heterogeneities in color, but the samples are predominantly blue-gray.  They appear fairly pure, but do have a few veins with discoloration along them.  Under the petrographic microscope all samples appear to be cordierite, but grains have a small amount of alteration and some microcrystalline inclusions. Sampled measured had fracture surface. (Ring Silicates) Original ASTER Spectral Library name was jhu.nicolet.mineral.silicate.cyclosilicate.solid.cordie2.spectrum.txt
Mineral:  Cordierite Mg2Al4Si5O18

Sample No.: cordier.2

XRD Analysis:  The sample contains predominantly cordierite but is 
contaminated with another unknown mineral with a major peak at 
3.015 angstroms.

Chemistry:  Microprobe analysis found grains measured to be 
homogeneous within and between grains.  Average of 9 analyses 
shows that this is not the pure magnesian end member of the series 
with sekaninaite, (Fe+2, Mg)2 Al4Si5O18:

SiO2	49.02
Al2O3	35.33
FeO	4.50
MgO	11.04
CaO	0.04
K2O	0.02
Na2O	0.33
TiO2	0.01
MnO	0.07
	_____
Total	100.44
