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!
While Menge (one of South Australia’s earliest geologists) believed he had found precious opal here, it has been shown to be only common opal. The purple colouration found in some pieces may have been the reason for Menge's erroneous report.