Vote for your favorite mineral in #MinCup26! - Sphalerite vs. Anorthite Both zinc ore Sphalerite and calcium plagioclase feldspar Anorthite have perfect cleavage that will split cleanly if you hit them with a hammer, but only one can claim a larger split of your votes!
Schooner (1955) says that it "used to be found in magnificent specimens at the small cut above the main part of the Strickland Quarry. Water from the adjacent Schoonmaker shaft, in flowing over a ledge of schist, decomposed the sulphides and mica, producing this hydrosoluble sulphate in limited abundance when the pumping was halted for a while." In Schooner (1958) he elaborates: "At times, especially when water was being drained down over the ledges, the author saw several square feet of rock surface completely covered with reniform pickeringite. Even leaves and twigs, on the ground below, were incrusted. The color was frequently pure white, and the material was solid enough to obtain in sizeable pieces. A peculiar mass, over an inch thick, was found under an overhanging ledge in the principal part of the quarry."
