BY W. F. PETTERD, C.M'.Z.S. 61 



96. Cuprite (Red Oride of Coyper). 



In the vicinity of Mt. Lyell this mineral occurs in some 

 abundance in finely-formed isometric crystals, which, both 

 as regards size and colouration, are of the prevailing octa- 

 hedron habit and its modifications. They are often 

 attached to or partially embedded in blocks of nodular 

 limonite, and occasionally the cavities in the nodules are 

 literally coated with the bright, sparkling mineral, which 

 from its ruby colour contrasts well with the brown iron 

 oxide. The Ip.tter is often stained a shining black with 

 manganese oxide and stilphnosiderite. Recently obtained 

 in considerable quantity, intermixed with iron oxide (tile 

 ore), at the Eastern P. A. Mine, Scamander River; also In 

 limited quantity at Curtin-Davis Mine, Dundas. 



97. Cyanite (Silicate of Aluminium). 



A pale-blue mineral, crystallising in the triclinic system, 

 and usually occurring as long, bladed, four-sided prisms, 

 which are irregularly terminated, and embedded in mica- 

 schists. It has been detected at Clayton's Rivulet. River 

 Fcrth. 



98. Cyanosite (Sulphate of Copper). 



Originates from the decomposition of cupriferous sul- 

 phides ; generally occurs stalactitic or as an amorphous 

 efflorescence in old mine workings. Colour : Various 

 shades of blue to bluish-green. From adit. North 

 Valley, Mt. Bischoff ; Gad's Hill Range, Upper Mersey 

 River, after a brass-yellow variety of chalcopyrite, often 

 intermixed with blebs of galena and blende ; Rio Tinto, 

 Savage River, and the old drives at the abandoned Aus- 

 tralasian Slate Quarry, Back Creek, at which place it is 

 commonly intermixed with the black oxide of copper ; in 

 the No. 4 level at Mt. Lyell, as an incrustation derived 

 from the leaching of cupriferous pyrites in the country- 

 rock. 



99. Damourite (Hydrated Sdicate of Aluminium and 



Potassium). 



A rock-forming mineral of common occurrence; it is an 

 altered muscovite-potash mica — which forms one member 

 of a group of alteration products often termed hydro- 

 micas. It has a pearly lustre and unctuous feel, after the 

 manner of ordinary t'alc. It passes from the distinctly 

 fibrous variety known as sericite to that of a compact 

 nature which is termed pinite. It may not only be derived 

 in some of its forms from the alteration of muscovite. 



