Mineral:  Monticellite CaMgSiO4

Sample No.: minticell.1

XRD Analysis:  After treatment with sodium acetate solution to 
remove calcite, XRD showed the sample to be pure monticellite.  An 
extremely weak calcite band in the infrared spectra shows that a 
very minor amount of calcite remains.

Chemistry:  Microprobe analysis indicated homogeneity within and 
between grains.  There is a small amount of substitution of Mg by Fe, 
resulting in departure from the ideal formula.  Average of ten 
analyses:

SiO2	37.26
Al2O3	0.01
FeO	5.14
MgO	21.69
CaO	34.94
K2O	0.02
Na2O	0.02
TiO2	0.03
Cr2O3	0.04
	_____
Total	99.15
