Description
Schist with coarse chloritoid crystals (up to 1/8 inch) without preferred orientation. These crystals grow across the foliation developed in the schist, but appear deformed. Chloritoid is a silicate mineral made in metamorphism. It also contains garnet, muscovite, chlorite, feldspar, and quartz.
The thin section shows a large chloritoid grain, and euhedral garnet. Fine-grained muscovite and biotite are present, along with strings of an opaque, likely graphite.
This rock is from the garnet zone in the Barrovian metamorphic sequence (intermediate metamorphism).