18 THE MINERALS OF TASMANIA. 



shows a remarkable play of bright colours — blue, red, and 

 yellow ; and a lesser amount of arsenopyrite and chal- 

 copyrite, the latter sometimes superficially altered to native 

 copper. The association, outside the metallic minerals, 

 constitutes a mass which has received the rock name of 

 limurite, and which has been fully described by Zirkel (N. 

 Jahrbuch fiir Mineralogie, 1879). The occurrence at 

 North-East Dundas is only paralleled by that of the 

 original locality in the Pyrenees. The Tasmanian occur- 

 rence has been microscopically and macroscopically 

 detailed by Mr. W. H. Twelvetrees and the writer (Pro. 

 Koy. Soc. Tas., 1897, pp. 1-6, pi. hoc. cit., 1898-9, pp. 

 1, 2, 56, and 59). 



The following are excerpts from the papers referred 

 to: — "Macroscopically the axinite is found in large lus- 

 trous crystal masses, the individual crystals often reaching 

 half an inch in length, thus forming specimens of great 

 interest to the mineralogist. The calcite is at timen 

 obtained in somewhat large masses, in which are oftei- 

 imbedded isolated crystals of axinite, which can be readily 

 freed from the matrix by digestion in acids. The actino- 

 lite varies from felted aggregations of microscopic size to 

 radiating collections of blades, occasionally some inches in 

 length, in the latter case presenting unusually fine 

 examples of the species. Various metallic minerals are 

 found as accessory constituents, of which pyrrhotite is 

 apparently most abundant ; but pyrite. chalcopyrite, and 

 more rarely leucopyrite occur in patches of variable size 

 throughout the rock. These are decomposed on the sur- 

 face to iron oxide, thin films of native copper, and small 

 quantities of the carbonates of the same metal. In thin 

 sections, when examined under the microscope, the bulk 

 mass of the rock is seen to consist of axinite, actinolite, 

 and calcite, with some hornblende. The other minerals 

 appearing in lesser quantity are quartz, chlorite, tour- 

 maline, and granular sphene." Details of micro-examina- 

 tion : Axinite. — 'This is in large irregular, and also 

 sharply-defined crystals, in section of a pale-lavender colour 

 to a deeper shade of the same tint. Interference colours, 

 yellow, blue ; sometimes interpenetrating twins. Cleavage- 

 lines irregular. Pleochroism scarcely perceptible. The 

 axinite has enclosures of quartz and fibrous hornblende, 

 and has been replaced occasionally by clear quartz and 

 vermicular chlorite, the latter light-^green in colour, pleo- 

 chroic, showing fixed dark cross, and polrrising steel-grey. 

 The quartz is very clear, and contains small prisms and 



