Chlorite Quartzite
Credit Line: Mineralogical and Geological Museum at Harvard University
Object number: BILLINGS-NH150
DescriptionFine-grained grey-green metamorphic rock. The majority of the rock has thin layers of < 1mm-scale layering of quartz and chlorite, but the other two pieces of this rock are ~2 cm wide vein that has a larger grain size, but similiar mineralogy. Quartz grains are grey and average <1 mm chlorite grains are dark green and <1 mm. Quartz in the vein is ~0.5 mm, plagiocalse is white and ~0.5 mm, chlorite is ≤1 mm, and biotite < 1 mm.