Willemite

A botryoidal mass of translucent, greyish, blue-green willemite on a plate comprising tightly intergrown fans of colourless-grey willemite crystals. The back of the botryoidal structure (as seen in Exhibit 1) is covered with a thin layer of reddish-brown willemite crystals (the variety known as troostite). 

The specimen is from the collection of A. Glen Smith, which was donated to National Museum of Australia in 1982; it is now housed at Geoscience Australia, in Canberra.