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!
The tourmaline from the locality is 71% end-member dravite. Petersen, O. et al., 2002, Dravite from Qarusulik, Ameralik Fjord in Southwestern Greenland, extraLapis 3, p.42-46