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): In 1987, sharp octahedral crystals of green to purple zoned crystals (< 6mm) were found in cavities in quartz with calcite and iridescent pyrite from recent workings on the Smith vein. [...] The fluorite octahedra have green cores with later purple and colourless zones, and covered areas to about 40 x 20 mm (D.R. Hacker Collection). On the opposite side of the same level, pale green unzoned octahedra have subsequently been found (D.I. Green, pers. comm.)."
