BY W. F. PETTERD, C.M.Z.S. 161 



299. Silver, Native. 



The free or native metal is not infrequently met with 

 on all the silver-lead mining fields of the State, but never 

 in large quantity. Although occasionally in arborescent 

 patches of extreme tenuity, it more commonly affects a 

 capillary form, varying from fine hairs to wire-like fila- 

 ments. In habit it occurs in irregular tangled growths, 

 but rarely showing any sign of crystalline structure. The 

 surface of the metal is always somewhat discoloured by 

 oxidation ; usually yellowish to even almost black. It is 

 invariably a secondary mineral, reduced from the state of 

 sulphide, or deposited from salts in solution. It may 

 reasonably be assumed that much of the capillary silver 'S 

 produced from circulating solutions through the reduction 

 of metallic sulphides. This is illustrated at the Magnet 

 Mine, by the deposition of hair-like entangled patches of 

 native silver nestling in the fractures and cleavages of 

 zinc sulphide, evidently resulting from the effect of sul- 

 phuretted hydrogen. It also occurs as minute frondose 

 branching patches in gossan at the Penguin Silver Mine, 

 at the Murchison, at Tullah, and at several of the Zeehan 

 mines. It occurs in the same form and under like con- 

 ditions in clefts in the siliceous lode material of the Hamp- 

 shire Silver Mine, where it was the principal ore of the 

 metal : on galena in attached flaky masses, Owen Meredith 

 Mine : in and on calcite, ankerite, and blende at the 

 Godkin Mine, Whyte River. At this mine some exception- 

 ally fine examples have been produced, some having arbor- 

 escent clusters of microscopic crystals, and occasionally 

 small vughs are coated and partially filled with the fibrous 

 metal ; in gossan with embolite, South Curtin and Davis 

 Mine, Dundas. At the Hercules Mine some remarkable 

 finds of the metal have been made, showing the wire-like 

 filaments growing amid and embracing crystallised masses 

 of cerussite. This occurrence was, perhaps, the finest 

 noted in Tasmania. 



300. Smaltite (Diarsenide of Cobalt). 



A tin-white mineral, but subject to superficial tarnish. 

 It is fairly hard = 5'5 to 6, and has a fine-grained to 

 uneven fracture. It is isometric in crystallisation, usually 

 affecting the cube, octahedron, and their modifications. It 

 is an important ore of cobalt, containing empirically from 

 11 to 28 per cent, of fhat metal, with small quantities of 

 iron and nickel. It commonly occurs in the amorphous 

 condition. It has been stated to occur as an almost solid 



