38 THE MINERALS OF TASMANIA. 



mixed with solid compact magnetite. A parallel discovery- 

 was made at Carn Chuinneag, in Ross-shire, Scotland 

 (" Summary of Progress " for 1903, p. 58) ; and at the 

 Renison Bell Mine it occurs in a dense pyrrhotite, which 

 is also extremely unusual for this m-ineral. Occurs of 

 unusual habit at Mayne's Mine, Heemskirk. The colour 

 varies from a pale dull-gray to almost black, and is com- 

 monly of a radiated fibrous structure, in botryoidal and 

 reniform shapes. Where concentric structure is well- 

 defined, the internal colouration is in bands of regular 

 width of various shades of gray to brown. In all essential 

 characteristics this occurrence exactly corresponds with 

 what is known as " wood tin " in Cornwall. An acute 

 pyramidal intensely black variety, representing: what has 

 been termed sparable or '' needle '' tin in the European 

 mining districts, occurs at Welsh's tin find near the five- 

 mile on the Waratah-Corinna-road. The crystals are 

 minute, very pointed, and a good imitation of the Old 

 World form. At Mt. Agnew the alluvial tin is contamin- 

 ated by plentiful grains of chromite, while near the Hus- 

 kisson, to the north-west of the Renison Bell Mine, the 

 tin ore is intermixed with osmiridium, derived doubtless 

 from the adjacent serpentine rock. At the Stanley River, 

 South Esk, Pioneer, and many other alluvial mines mona- 

 zite is of common occurrence in the form of minute yellow- 

 ish particles. At the Shepherd and Murphy Mine, Bell 

 Mount, it occurs in a series of small lodes, closely associ- 

 ated with wolframite, bismuthinite, achlusite and fluorite. 

 At this mine groups of geniculated crystals are somewhat 

 common, often approaching the rutile law. 



" The radiating fibrous variety, with concentric differ- 

 ently-coloured zones — called toad's-eye tin — occurs in the 

 alluvial deposits occupying the western slopes of Mt. 

 Heemskirk in the vicinity of the Federation Mine. . . . 

 Cassiterite has recently been found on the Oonah lease in 

 Zeehan. It occurs with quartz and pyrite, forming a fine- 

 grained granular aggregate cemented by quartz in the 



oxidised portion of the lode Analyses of the 



stannite of the Oonah Mine have disclosed a certain con- 

 tent of tin in the form of oxide. The proportion occurring 

 in the stannite is variable, and may represent as much as 

 15 per cent, of the total tin contents. This oxide is, in 

 all probability, finely-divided cassiterite. 



In all localities quartz and cassiterite are always 

 closely intermixed ; and at times remarkably well- 

 developed crystals of the latter are found implanted on 



