162 Dr Turner's Analysis of LepidoliU 



Art. XXXIII. — Analysis of Two Varieties of Lepidolite. 

 By Edward Turner, M.D.F.R.S.E. Lecturer on Che- 

 mistry, and Fellow of the Royal College of Physicians, 

 Edinburgh. Communicated by the Author. 



While engaged a few months ago in analyzing several spe- 

 cies of lithion-mica, my attention was attracted by a pretty 

 rose-coloured mineral, said to be a mica from the Uralian moun- 

 tains, in the possession of my friend Dr Anderson of Leith, 

 which gave distinct indications of the presence of lithia. 

 It occurs in groups of crystals like the Zinnwald mica, and 

 its laminae are about the same size, some of them being half 

 an inch in diameter. Its specific gravity, after the air had 

 been expelled from it by boiling water, was 2.855. It fuses 

 readily before the blowpipe, tinging the flame of a red colour, 

 and forms an opaque and beautiful white pearl on cooling. 

 It suffers no appreciable loss in weight when heated to redness. 



To show that this mineral is rather a lepidolite than a mica, 

 I have compared its composition with that of a very pure va- 

 riety of the common Swedish lepidolite. The specimen em- 

 ployed for the purpose has the same character before the 

 blowpipe as the preceding, and its specific gravity, after be- 

 ing boiled for a short time in water, was 2.8469. It loses on- 

 ly l-1000th of its weight by being heated to redness. 



These analyses, in which I was assisted by Mr Gregory, 

 were performed by the method which was minutely described 

 in a former paper,* and, therefore, it will be superfluous to 

 give more than the results of them at present. 

 Results of Analysis. 



99.61 99.44 



A trace of lime was also detected in the first variety. 



* See this Journal, vol. iii. p. 261. 



