12 THE MINERALS OF TASMANIA. 



field, and Springfield. It is formed as stalactites in con- 

 nection with the limestone caves at Chudleigh, Mole Creek, 

 and probably in other localities of like nature. At the 

 Magnet Silver Mine small and slender, but highly 

 resplendent, crystals have been observed in the southern 

 workings. They were implanted in irregular groups on 

 sulphide ores. A small crystal, when tested with the blow- 

 pipe on coal, gave a minute bead of metallic lead, thus 

 showing an approximation to the mineral which has 

 received the name of tarnowitzite, from Silesia ; but other 

 examples from the same occurrence did not give this result. 

 It may therefore be concluded that the replacement of 

 portion of the calcium by lead was accidental, and that the 

 proportion of the latter element was not suflScient to form 

 the species referred to, presuming that in the Silesian 

 occurrence it is a homogeneous compound, which is doubtful. 

 At Bridgewater aragonite is found in connection with the 

 lime quarries of the locality. Occasional bunches of irregu- 

 lar crystals occur in the dolomite of the Magnet with 

 solated crystals of remarkable length and purity. 



24. Argentite (Snlphide of Silver). 



This mineral is only known in the crystallised form as 

 rude, irregular octahedra and illformed cubes. Its 

 common habit is in dendritic patches and earthy masses. 

 It is only known under the name of '' silver glance." It 

 is an extremely uncommon mineral in this island. At the 

 old Godkin Extended Mine, Whyte River, it has been 

 found in an almost pure state, assaying at the rate of 

 many thousands of ounces of silver per ton — as worn, 

 rounded " slugs," intermixed with lumps of huascolite and 

 galena. The slugs were of small size, rarely exceeding an 

 inch in diameter, and were coated with a powdery black 

 decomposition product. At the old Hampshire Silver Mine 

 it occurred many years ago in the form of minute indis- 

 tinct crystals implanted sparingly on other minerals and 

 in cavities in the veinstone (W. R. Bell). At the Bell's 

 Reward section, Whyte River, a few minute particles 

 occurred in com.pany with some embolite ; they were 

 scattered throughout a decomposed silicious matrix of 

 doubtful origin. At an old mine at the Scamander River 

 a small quantity was obtained in a silicious gangue with 

 arsenopyrite. At the Magnet Mine small patches and 

 scales occur in contact with highly argentiferous galena, 

 and at the Spray Mine at Zeehan flakes of practically pure 



