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): "From an old working on the Deer Hills Quartz lode [NY31453626] (M.P. Cooper Collection, det. University of Manchester Institute of Science and Technology (UMIST): IR.)"
Deer Hills, Caldbeck, Allerdale, Cumbria, England, UK