Pyromorphite on Coronadite

This magnificent cabinet specimen of oil green Pyromorphite on black Coronadite is from the MMM mine at Broken Hill in New South Wales, Australia, one of the world’s most famous mineral localities.  The approximately 12.5 x 6.5 cm face is almost entirely covered in delicate acicular Pyromorphite crystals with just a few patches of the Coronadite showing through.  Coronadite is a complex mineral despite its relatively simple sounding chemistry, a lead-manganese oxide-hydroxide.  Complications arise due to its various valency states of oxidation, of which I will draw the line here.  It is however a well-known mineral in the Broken Hill mines and its association with Pyromorphite is somewhat uncommon, yet not rare.  The Pyromorphite forms as hexagonal acicular prisms up to about 8 mm tall and exceptionally 1 cm, with flat pinacoids and also hopper terminations.  Around the sides, micro-crystals of Pyromorphite can be seen coated in a thin black film of Coronadite.  Without doubt, a beautiful and fine oil green Pyromorphite on Coronadite from Broken Hill.