Pyromorphite on Coronadite

A magnificent cabinet specimen of lime and oil green Pyromorphite crystals on black Coronadite from the MMM mine at Broken Hill in New South Wales, Australia.  The approximately 9 x 8 cm triangular display face is three-quarters covered with delicate acicular Pyromorphite crystals and a roughly 3 x 3 cm uncovered area of silvery black Coronadite.  The Pyromorphite distinctly divides into two phases or groups: smaller, fine acicular yellowish lime green crystals and larger, oil green hexagonal prisms, typically with simple hopper terminations.  The smaller crystals average, say, 2 to 3 mm while the larger are about 8 mm, with taller exceptions.  Coronadite is a lead-manganese oxide-hydroxide.  Both Pyromorphite and Coronadite are well-known minerals from the Broken Hill mines.  Many micro-crystals of Pyromorphite covering the area of Coronadite are coated in a thin black film of Coronadite.  A very fine cabinet specimen of lime and oil green Pyromorphite on Coronadite from the MMM mine at Broken Hill.