was intrigued both by the (somewhat blurry) image of the mineral cluster and the likely candidates suggested, so in an effort to educate myself I've looked up both Smithsonite and Brochantite.
Although Smithsonite is a zinc carbonate, it does form a "solid solution series" with other carbonates which means it can include several other metals within its composition. Copper is one and will produce a nice green colour.
Brochantite is also another strongly green coloured copper mineral, however its typical form is in fibrous or needle like growths.
As best as I can tell, the photo shows a "bubbly", rounded or botroidal textured pale green specimen which is more typical of a carbonate like Smithsonite.
I hope this helps with the ID,
Tasmanian Gemstone and mineral specimen Prospecting