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 (1991): "small, rounded, greenish to khaki crystals encrusting quartz. The mineral frequently contains a high proportion of phosphate and passes insensibly into pyromorphite. Many specimens are of intermediate composition."
Driggith Mine, Caldbeck, Allerdale, Cumbria, England, UK