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!
England (1980): "Isolated pockets of unaltered azurite crystals occur throughout the workings but these crystals rarely exceed 1/2 inch in diameter. An interesting occurrence in the walls of the open cut above No. 2 adit is the presence of azurite crystals with malachite-replaced centers. This would indicate an apparent additional short period of azurite growth after replacement of the original azurite crystals. Perhaps this was favored by a recent lack of groundwater movement in some sections of the deposit. The azurite usually occurs as single isolated crystals or small groups. In the open cut above No. 2 adit, exceptionally fine chain-like groups of prismatic crystals were found in a soft claystone in a small and apparently unique pocket. Cleaning of these specimens required several hours painstaking work and in many cases careful repair was essential to preserve these unusual groups intact."
Sir Dominick Mine, Daly gorge, Yudnamutana District, Arkaroola, Pastoral Unincorporated Area, South Australia, Australia