Foote and Bradley — Solid Solution in Minerals. 29 



VI 



Nephelite from Vesuvius. 



Si0 2 42-53 



TiO, 0-01 



A1 4 0, 33-92 



Fe 2 3 0-30 



CaO 1-91} 



MgO 0-07 



K,0. 5-82 , 



Na s O - 15-12 J 



H a O 0-13 



Impurities 0-24 



Ratio 

 2-11 



1-00 



y 1-02 



VII 



Nephelite from Vesuvius. 

 Different specimen from VI. 



Eatio 



SiO, 43-34) 



Ti0 2 trace \ l 15 



Al.O, 3375 ( 



PelO, 0-50 \ 10 ° 



CaO 2-20] 



MgO. 0-24 1 



K 2 4-34 f i0d 



Na a O 15-66 J 



H„0 0-23 



100-11 



100-26 



"We consider tbe seven analyses given above to be the best 

 which have been made on nephelite. A considerable number 

 of other analyses have been made, however, and we give 

 below a summary of the ratios obtained from the analyses 

 given in Dana's Mineralogy, page 425. The numbers are the 

 same as in the Mineralogy. 





Table 



III. 





s obtained from Analyses of 



Nephelite given in 



Dana's Mint 





Si0 2 





A1 2 6 etc. 



Na 2 etc 



No. 1. 



2-21 





1-00 



1-00 



2. 



2-25 





« 



•99 



3. 



2-17 





« 



1-00 



4. 



2-29 





a 



•95 



5. 



2-20 





a 



•91 



6. 



2-24 





a 



1-04 



7. 



2-18 





(« 



1-02 



8. 



2-24 





(C 



1-01 



9. 



2-31 





(i 



•97 



10. 



2-60 





(t 



1-16 



11. 



2-24 





(i 



1-05 



12. 



2-06 





a 



•94 



13. 



2-14 





(< 



•93 



14. 



2-29 





a 



•97 



15. 



2-19 





a 



•98 



The summary of the ratios obtained in the seven analyses 

 first given is as follows : 



