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!
Cooper & Stanley (1990): "As pale sea-green blades and radiating sprays of crystal sections to 20 mm with leadhillite, from the outcrop workings on the South vein in higher Roughton Gill (Kingsbury Collection, BM(NH)). Recently found in situ in the same area forming thin grey laths to 2 mm with mattheddleite, leadhillite, caledonite, and scotlandite in pods of altered galena (D.I. Green in prep.)."
Habit:
blades; radiating sprays of crystal sections to 20mm; thin laths to 2mm
