1 64 THE MINERALS OF TASMANIA. 



mineral, siderite; occasionally druses of crystals occur of 

 various colours, up to J -inch in size. The crystals are often 

 well developed, presenting the octahedron with small 

 planes of the cube terminating the corners. Fine octa- 

 hedral twins on the spinel law are not uncommon. They 

 sometimes vary from a resin to a greenish colour, but the 

 prevailing tint is a shade of dark-brown. Abundant in 

 groups and masses of amber-coloured crystals at the Mari- 

 posa and other mines at North-East Dundas. At the 

 Silver Crown Mine at Zeehan bunches of somewhat large 

 crystals occur of a brown colour. At the Godkin Mine, 

 Whyte River, a richly argentiferous blende occurs in amor- 

 phous masses — it is of a mahogany-brown colour with a 

 dull lustre. It is found associated with patches of native 

 silver and masses of galena in a white and dark coloured 

 calcite, and more rarely in ankerite. At the Heazlewood 

 Silver-lead and other mines in the vicinity minute but 

 remarkably well-formed complicated crystals are abund- 

 ant. They are of a clear yellow to red colour, and are 

 usually obtained implanted in the fractures of siderite or 

 quartz with crystals of galenite. At the Heazlewood Mine 

 it also occurs more rarely, in beautiful sharp-angled 

 crystals v. hich have a purple, green, and red metallic tarn- 

 ish ; abundant in a massive form of a black colour, east 

 branch of the Hellyer River ; plentifully and thickly dis- 

 sem.inated in a vein at the Hampshire Silver Mine, where 

 it presents a peculiar copper-red colouration ; of a dark- 

 brovv'n to black colour wdth chlorophane and various forms 

 of pyrites, Mt. Bischoff ; scattered throughout a dyke 

 formation, with galena in granite rock, Meredith Range ; 

 as minute crystals of a pale-green colour with galena, 

 Australasian Mine, Dundas ; in limited quantity, Ben 

 Lomond ; in a lode, which is mainly composed of a mix- 

 ture of this mineral, arsenopyrite, and galena, Scamander 

 River ; Penguin River Silver-lead Mine ; Mt. Claude ; 

 Middlesex, with pyrites and galena ; often highly aurifer- 

 ous, but in very small quantity, Lefroy and Mathinna. 

 A peculiar variety of phosphorescent blende occurs at the 

 Castray River ; it was obtained in trenching across a 

 decomposed lode formation as rounded lumps, brown in 

 colour, and of small size, wdth masses of galena and 

 pyrites as accessory minerals. The phosphorescent charac- 

 ter is clearly distinct when the material is struck or 

 scraped with a knife-blade. It is locally known as '' elec- 

 tric calamine." At the Hercules Mine a comparatively 

 small portion of the massive zinc sulphide show^s strong 



