Willemite (w. mimetite)

malachite; mimetite

A plate comprising intergrown crystals of willemite (individually to 4 mm), typically equant and colour-zoned (Exhibit 2). Some have black cores (possibly due to included sulphides) and some have orange-yellow cores (perhaps due to iron oxide inclusions); in most cases these cores are sheathed with colourless, gemmy willemite. Radiating sprays of pale yellow mimetite crystals (to 5 mm) and sparse, minute spherules of malachite rest on the willemite.
This was specimen number 902 in the collection of Clement Victor Latz, which was donated to the Australian Bureau of Mineral Resources in 1976. There is no record of earlier provenance or of location in the mine.