174 



THE MINERALS OF TASMANIA. 



habit, with the faces vertically striated. It occurs thickly 

 coating cavities in the harder ferro-manganese gossan as 

 small radiating blue-green tufts packed, in many instances, 

 closely together, and covering fairly large surfaces. Under 

 the lens it is a mineral of considerable attractiveness 



323. Talc (Hydrated Silicate of Magnesium). 



A beautiful snow-white form occurs at the Arthur Kiver 

 near its junction with the Hellyer. On the west branch of 

 the Clayton Rivulet this mineral occurs as a vein of a 

 yellowish-white colour, and is about 2 feet in width. About 

 1 mile north of Remine, on the coast, a beautiful semi- 

 transparent form exists in considerable abundance ; it 

 abuts upon the serpentine outcrop; it varies in colour 

 from translucent whit^ to a clear pale-green. A large 

 formation occurs on the Meredith Range, near the Castray 

 River; it is massive, compact in structure, and very pure; 

 the prevailing colour is a beautiful pale sea-green, shining, 

 and extremely unctuous. Of subcrystalline structure in 

 large masses. Magnet Range ; in radiating masses with 

 cassiterite, North Valley, as well as impure and massive 

 at other places at or near Mt. Bischoff; Asbestos Mount- 

 ain, near Beaconsfield ; near the Parson's Hood Mountain ; 

 Ben Lomond ; Blue Tier. 



324. Tasmanite (Hydrocarbon). 



A grey, earthy, arenaceous shale, more or less impreg- 

 nated with circular, punctuate, brown, microscopic fossil 

 spore cases of a highly resinous nature, which have been 

 named Tasmanites punctatus (Newton). 



The spores yield an oily product in considerable quan- 

 tity, but of poor illuminatory power. As much as 100 

 gallons of oil has been obtained by distillation per ton 

 of shale. In beds of considerable extent on the banks of 

 the Mersey River. 



The American black paraffin shale has been found to be 

 -extremely rich in spore cases of a similar structure and 

 character to those so abundant in tasmanite. The origin 

 of the shale is supposed by some authorities to have been 

 the accumulation of the shell spores of a species of marine 

 algae, similar to that now existing in the Saragossa Sea. 



Dana states ("A Textbook of Mineralogy ") that this 

 hydro-carbonaceous substance is '' remarkable in contain- 

 ing sulphur, replacing part of the oxygen." 



