BY W. F. PETTERD. 25 
decomposed Diorite, abutting on to the lode, coating the faces of 
fractures ancl cleavage planes. In some instances flakes of the 
mineral several inches in diameter were detached. Rarely patches 
of small monoclinic crystals occurred, but this was exceptional. 
In vughs, occurring in the capping of the lode or the adjacent 
country rock, they were often found to be thickly coated with 
bunches of the mineral, of bright colouration and of great beauty. 
At the Adelaide Proprietary mine, at Dundas, this species is 
very plentiful. It commonly occurs in large columnar prisms, often 
several inches in length, that penetrate the vesicular ferro- 
manganese gossan that overcaps the lode. In the workings of 
this mine some extremely fine and beautiful specimens have been 
obtained, the mineral often coating white Dundasite, and ocasionally 
associated with crystals and large bunches of Cerussite and more 
rarely Anglesite. In some samples the red prisms penetrate the 
gossan intermixed with botryoidal Psilomelane and occasionally 
patches of Galena occur in the more solid portions; occurs on 
Embolite, Hay’s Prospecting Association, Heazlewood. 
Crocoisite has not been discovered in Australia. So far as 
examined this mineral has not been found to be argentiferous. 
75. CERUSSITE (Lead Carbonate). 
Occurs in more or less quantity wherever the primary lead 
sulphide exists. The Silver Queen, Sylvester, and Austral mines 
at Zeehan, the Maestries Broken Hill, Comet, and Adelaide Pro- 
prietary at Dundas, with the Godkin and Whyte River mines in 
the Heazlewood, district have afforded fine examples in massive 
amorphous, subcrystalline and well developed orthorhombic 
erystallizations. 
Occasionally it is permeated to some extent with one or other 
of the Silver Chloride group, when it assumes a grey-coloured 
amorphous form, which is locally known as “grey ore.” In this 
state it invariably gives high assay returns for Silver. It often 
occurs stained and encrusted with both green and blue Copper 
Carbonates, and in some instances found coated with a mixture of 
Antimony and Lead Oxides. Anglesite is a species closely 
resembling this mineral, and it is often intimately associated with 
it, but a simple qualitative analysis soon detects the different com- 
position, its habit of crystallization is another distinguishing 
character—Cerussite occurs in tabular forms, usually six-sided 
prisms with various terminations, and is often macled. 
76. CYANOSITE (Sulphate of Copper). 
Originates from the decomposition of Cupriferous Sulphides ; 
generally occurs stalactitic, or as an amorphous efHorescence in old 
mine workings. Colour, various shades of blue to bluish-green. 
From adit, North Valley, Mount Bischoff; Gad’s Hill Range, 
Upper Mersey River, after a brass-yellow variety of Chalcopyrite, 
it is often intermixed with blebs of Galena and Blende. 
