130 THE MINERALS OF TASMANIA. 



At Wombat Hill, about 5 miles from Waratah, the 

 granite on the road-side shows large crystals of this felspar 

 thickly dispersed throughout the mass. 



The localities mentioned afford the most remarkable 

 occurrences of orthoclase that have been detected. In its 

 normal condition it is naturally abundant throughout the 

 granite regions of the north-eastern and north-western 

 portions of the island. 



231. OsMiRiDiUM (Iridium and Osmium, in varying pro- 

 portions, with some Platinum, Rhodium, Ruthejiium, 

 and other Metals). 



This mineral is usually found in the form of thin, shin- 

 ing, tin-white scales, or irregular crystalline plates of small 

 siz^; but occasionally nuggets are obtained weighing up to 

 3 to 4 dwt. One such, from the Whyte River, near its junc- 

 tion with the Pieman, weighed 60 gr., the specific 

 gravity being 19'5. Another specimen of about the same 

 weight shows a distinct crystalline surface, and has the 

 appearance of an aggregate of crystals. A specimen has 

 been reported from the vicinity of the Heazlewood River 

 measuring about seven-eighths of an inch in diameter. It 

 has only been obtained in alluvial drift, but it doubtless 

 owes its origin to the serpentine and peridotites of the 

 region. At the Badger gold diggings, west of the Savage 

 River, as well as in the Savage itself, it has been obtained 

 in somewhat large quantities associated with gold and 

 menacanite. At the Castray River and vicinity it has 

 been worked under the same conditions, but intermixed 

 with considerable quantities of picotite and fragments of 

 chromite. At the Salisbury goldfield, near Beaconsfield, 

 it has been obtained in small quantity, and at the Huskis- 

 son River it occurs in comparative abundance. At the 

 Nineteen-mile Creek, which rises on the Bald Hills and 

 flows into the Savage River, two small nuggets were found, 

 with the normal scaly material, which weighed respectively 

 2 dwt. and 1 dwt. 4 gr. (F. W. Gill). 



Other members of the platinoid group, such as platinir- 

 idum, iridium, and platinum, have been reported to occur, 

 but their identification needs confirmation ; the lastmen- 

 tioned was stated to occur at the Wilson River, which falls 

 into the Pieman, 



Although it is known that a considerable quantity of 

 osmiridium is, and has been for some years past, won by 

 alluvial miners on the West Coast, mainly in the vicinity 

 of the Savage and Pieman Rivers, no information is avail- 



