Microcline Thin Section

A thin section image showing microcline grain in a coarse grained sandstone from estonia.

Microcline thin section. Prismatic crystals elongated along 001 or 100 perhaps the largest of any species to 50 m and 13 500 t. Add tags comment rate. In thin section microcline orthoclase and sanidine are distinguished by their twinning optical sign and 2v o.

To link to this object paste this link in email im or document to embed this object paste this html in website. It is characterized by cross hatched tartan twinning in crossed polars. Microcline is found in granite granodiorite pegmatite syenite and related plutonic igneous rocks that cooled slowly at considerable depth.

Can also display carlsbad twinning simple twins or lack twinning altogether. This combination leads to a grid pattern hence microcline displays gridiron twinning. Occurrence and associations.

Microcline is also common in metamorphic rocks in gneisses and in sedimentary rocks in arkoses and conglomerates. Microcline kalsi3o8 c 20 1m i nera ld t pub sh g v o. You can find the explanation on the alkali feldspar page.

Width of view 3 mm. In the field the indicators are color transparency occurance and luster. Width of sample 6 cm.

Tartan plaid or plaid twinning is a combination of albite and pericline twinning. It is the dead giveaway of microcline. Microcline is common in many kinds of silicic igneous rocks sediments such as arkoses and a va riety of metamorphic rocks.