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!
Kingsbury (1957): "small but well-defined prismatic crystals of phosgenite, associated with anglesite, on decomposed galena. The crystals of phosgenite are pale wine-yellow in colour, and of long prismatic habit, the larger of the two being about 8mm long and 2mm thick: both show well-developed terminal faces of c(001) and several small faces in the pyramid and prism zones, but the latter are in general very striated, with many small vicinal faces, and owing to the positions of the crystals in the cavity it is difficult to make out what most of the faces are."
Penberthy Croft Mine, St Hilary, Cornwall, England, UK