Cpx Thin Section

A diagnostic feature of members of the pyroxene group is the 110 cleavage that.

Cpx thin section. Alex strekeisen i vetrini della mia fantasia. Colour and pleochroism. It shows high relief inclined extinction and is optically negative with a 2v of about 85 o.

Usually colourless gray pale green or pale brown darker colours associated with fe rich varieties titanaugite is more distinctly coloured from brown pink to violet. They appear as pastels in places almost pearly white. Sub ophitic texture with clinopyroxene and plagioclase altered to clay xpl.

Acicular crystals of cr diopside. The rock illustrated in these images contains both clinopyroxene and orthopyroxene and the significantly higher cr 2 o 3 content of the clinopyroxene in this sample gives it a pale green colour in plane polarized light whereas the cr poor orthopyroxene is colourless a. In thin section it is clear with no pleochroism which distinguishes it from other amphiboles.

The dolomite is twinned and shows very high order interference colors. Actinolite also occurs almost exclusively in low grade metamorphic rocks particularly in meta basalts and meta gabbros where it is commonly associated with chlorite. Simple twin in basal section of clinopyroxene.

Nice trick to tell the difference between clinopyroxene and orthopyroxene in petrographic thin sections. Clinopyroxene xyz 2 o 6 optical properties.