PITCHBLENDE PROBABLY OCCURRING IN NEW SOUTH WALES. 33 



The Economic Value of the Mineral.— Since it has the 

 composition of a secondary pitchblende, it is to be expected 

 that it may occur, as the other secondary ones do generally, 

 in such quantities as to make its recovery payable. More- 

 over, it only contains such elements as are readily separated 

 from one another by the methods used to obtain pure 

 uranium and radium from Bohemian pitchblende. 



Two other Australian minerals containing radium have 

 come to the writer's notice. A monazite from Pilbarra, 

 W.A., was shown by Mawson and the writer 1 to give off 

 radium emanation when heated. Mr. Chapman, 2 noticed 

 carnotite, a vanadate of uranium and potassium, in a 

 sample of ore sent to him for analysis from the vicinity of 

 Olary, S.A. ; and Mawson discovered a new secondary 

 mineral davidite, containing uranium, potassium and 

 vanadium in the same ore. These South Australian 

 minerals occur in pegmatite veins as do most of the 

 uraninites. If further efforts are made to discover Bennett's 

 pitchblende in the New England district, it would be most 

 profitable to examine the pegmatite granites which occur 

 there. Uranium minerals are undoubtedly most readily 

 identified even in the field by their property of discharging 

 gold-leaf electroscope, their action on a photographic plate, 

 or the production of scintillations on a zinc blende screen. 



I wish to thank Mr. Card for having obtained and brought 

 to my notice the mineral I used in the experiments described 

 above, and also Mr. Bennett, who placed what information 

 he had as to the finding of it at my disposal. The writer 

 carried out his investigation of the mineral in the Chemical 

 Laboratory of the University of Sydney. 



1 This Journal, xxxvin, 1901, or Chem. News, July 1905, p. 39. 



2 Mawson, Trans. Roy. Soc. S.A., xxx, 1906. 



C— June 2. 1909. 



