322 



Spodumene and its Alterations. 



ANALYSES OF SPODUMENE. 



Silica, 



Alumina, 



Ferric Oxide, 



Mauganous Oxide, 



Magnesia, 



Lime, 



Lithia, 



Soda, 



Potassa, 



Water, 



I 



II 



III 



IV 



Goshen 

 (Julien.) 



ChesterficI 

 (Julien.) 



Mean of 

 I & II. 



Norwich | 

 (Smith \- 

 Brush.) 



68.27 



61.86 



62.57 



64.04 



23.73 



23.43 



23.58 



27.84 



1.17 



2.73 



1.95 



.64 



.64 



1.04 



.84 







2.02 



1.55 



1.78 



trace. 



.11 



.79 



.45 



.34 



6.89 



6.99 



6.94 



5.20 



.99 



.50 



.75 



.66 



1.45 



1.33 



1.39 



.16 



.36 

 100.63 



.46 



.41 

 100.66 



.50 



100.68 



99.38 



Sterling 

 (Smith & 

 (Brush.) 



64.50 



25.30 



2.55; 



.06 



.43 



5.65 



I i. 



99.89 



Sp. Gr. 



3.19 



3.185 



and 



3.201 



3.18 3.182 



My own three S. G. determinations were made npon quanti- 

 ties of 7.9, 3.6, and 5.5 grammes of mineral, respectively, and 

 show that the true Specific Gravity of unaltered Spodumene is 

 a little higher than that hitherto accepted. 



A considerable delay having occurred in the publication of 

 this paper since its reading before the Academy, advantage has 

 been taken of the opportunity to incorporate the latest results 

 of other analysts. 



Three good analyses of Spodumene have been recently pub- 

 lished, on specimens from the following localities : so that I 

 have been anticipated in the publication of the true composition 

 of the mineral. 



