COMPOSITION OF N.S.W. LABRADORITE AND TOPAZES. 



203 



the aluminium hydroxide taking down with it some of the fluorine 

 and sodium. 



The alumina was always tested by potassium bi-sulphate and 

 the silica by hydrofluoric acid purified from the commercial acid 

 by redistilling in a platinum retort. The calcium fluoride pre- 

 cipitates were tested by conversion into calcium sulphate or in 

 some other way. 



Analysis of Topazes. 







Fusion with alkaline 



Fusion with alkaline 







carbonates and silica. 



carbonates alone. 







1 



2 



1 



2 



Mudgee, 



Si0 2 



31-90 



3 1-84 



32-30 



32-46 



N.S.W. 



ALA 



56-62 



56-80 



59-70 



59-21 





F 



17-90 



17-00 









H 2 Oon 



ignit. -23 



•26 









H 2 Oby 



PbO -75 



•75 









107-10 



106-65 





Brazil 



Si0 2 



31-95 



32-16 



32-31 



31-90 32-18 





A1 2 3 



54-52 



54-61 



55-90 



56-45 55-88 





F 



14-62 



14-23 









H 2 Oon 



ignit. -23 



■30 



•26 



•24 -26 





H 2 Oby 



PbO. 2-12 



2-12 









FeA 









•10 -09 





103-44 



103-42 





New 



Si0 2 



31-73 



31-92 







England, 



A1 2 3 



55-62 



55-43 







N.S.W. 



F 



16-30 



15-92 









H 2 on ignit. -37 



•39 









H 2 Oby 



PbO 1-07 



1-07 









Fe 2 3 



•12 











105-21 



104-73 







Analy, 



ses of topazes from other sources 







Curran. 



Penfield and Minor, Am. J. S. 94. 



Liversidge. 





N. S. Wales 



Utah. Stoneham. 



Brazil. *i 



Shoalhaven, N.S.W 



Si0 2 



30-29 



31-93 



32-28 



3253 



28-19 



A1 2 



3 60-90 



56-25 



56-33 



55-67 



62-66 



F 



15-05 



20-33 



18-56 



•15-48 



1401 



H 2 



•40 



•19 



1-04 



2-45 







106-64 



108-71 



108-17 



106-13 



104-86 



* Dull and impure. 



