Size  6cm x 3cm
The greenish yellow coating on this speciman was formally identified as Mottramite.  It was found in one small area at the mine many years ago, and sat untouched in a box for years until I got it tested at the SA museum.  Not in crystalline form , but an unusual species from an unusual locality.
Mindat lists Iron Monarch as the only south australian locality, and there it was all micromount size, no cabinet specimans.