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!
"Thomsonite often forms smooth, translucent, grey to pale brown hemispheres with a resinous lustre. The hemispheres are up to 3 mm in diameter and are composed of elongated plates which are exceedingly thin. Other forms include compact fibrous sheafs and tuffs which retain the grey translucent appearance of the globular form. The tips of these fibres sometimes appear as if they have been partly fused together. Hemispheres of thomsonite from Bundoora sometimes show secondary radiating needle and sheaf-like growths issuing from the surface. The needles show natrolite-like terminations."
Boral Limited quarry, Bundoora, City of Whittlesea, Victoria, Australia