Staurolite

A very sharp cluster of brown crystals to 2.7cm. Unfortunately no specific locality data other than “Virginia”. George purchased this from John Betts in 2004. It is ex Lincoln Sherk MD, who was John Betts grandfather. Dr. Sherk  (1890 to 1969) founded Bethel Hospital in Camden NJ and was a founding member of the Delaware Valley Earth Science Association. Ex George Loud.

Locality: Virginia

Composition: layers of Al2SiO5  (kyanite composition) and AlFe2O2(OH)2 that alternate parallel to (010). Staurolite also contains magnesium, zinc, and manganese, which can substitute in the iron site, and trivalent iron, which can substitute for aluminum.