140 



THE MINERALS OF TASMANIA. 



257. Przibramite (Sulphate of Zinc and Cadmium). 



Cadminiferous blende has been obtained near the 

 Scamander Kiver, on the East Coast ; at several localities 

 in the Ben Lomond district ; and more sparingly at the 

 Heazlewood. 



258. Psilomelane (Hydrous Manganese Manga^iate). 



Amorphous, botryoidal, and stalactitic, of a dark colour, 

 with submetallic lustre. The common mode of occurrence 

 is in the stalactitic habit in cavernous gossan, and it is 

 often very impure. 



It is abundant at the Penguin River; at the Heazle- 

 wood and Dundas it occurs in the lode outcrops, and forms 

 considerable proportion of the outcrops ; at the Heazle- 

 wood and Magnet it also occurs in quantity. 



259. Pycnite. (See Topaz.) 



26('. Prosopite (Hydrous Aluminium and Calcium, 

 Fluoride). 



Occurs as a granular powder, which is often kaolinised. 

 Its probable origin is from the decomposition of topaz 

 porphyry. It occurs closely intermix-ed with partially 

 decomposed green tourmaline at Mt Bischoff. 



261. Proustite ( Sulphar senile of Silver). 



This attractive mineral was first detected in minute 

 bright crimson patches, intermixed with other minerals, at 

 the Bell's Reward Mine, Heazlewood, and has more recently 

 occurred at many of the silver-lead mines, but only in 

 small quantity. At the Magnet Mine it oft^n occurs as 

 patches of extreme tenuity coating the dolomite gangue. 

 These patches are at times intermixed with or surrounded 

 by native silver, appearing as if the latter were derived 

 from its decomposition. A small number of bright, sharply 

 cut crystals have occurred, but they are of extreme rarity. 

 At the Hercules Mine the surface of the schist rock, and 

 at times the complex mixture of zinc and lead sulphides^ 

 are often coloured red by a thin coating of this mineral, 

 with which the dark ruby silver, pyrargyrite, is sometimes 

 associated. At the Zeehan mines it has been detected, 

 notably at the British-Zeehan Mine. It has been found at 

 the North Farrell Mine, at Tullah ; at the Long Tunnel 

 Mine, at Heazlewood ; and in several other localities ; but 

 always in small quantity, and usually as thin films. 



