Composition:

Petrographic Description:  A granular hypidiomorphic rock composed of 
65% orthoclase, 30% quartz, 3% pyroxene, 1.5% riebekite, and 0.9% albite.  
The turbid orthoclase subhedra are highly albitized perthite frequently 
showing Carlsbad twinning, while interstital to these are a few albite 
anhedra.  The anhedral quartz is somewhat undulose.  A bright green, 
slightly pleochroic pyroxene has been largely replaced by dark blue to 
brown pleochroic riebekite.  In addition, there are minute blue riebikite 
needles disseminated throughout the sample.  The spectrum shows extremely 
weak carbonate features, but no calcite was seen in thin section nor was the 
rock analyzed for CO2.

Microprobe Analysis:  The microprobe analysis revealed an orthoclase-rich 
compsition (Or97) with perthitic exsolution.  The sodic pyroxene (aegerine) 
proved to be homogeneous in composition, as was the riebekite.

Chemical Analysis:
SiO2  73.44
CaO  0.39
TiO2  0.21
Na2O  4.96
Al2O3  12.29
K2O  4.94
Fe3O3  2.11
H2O  0.56
FeO  1.6
P2O5  0.0
MnO  0.08
MgO  0.02
TOTAL  100.6
