348 



Spodumene and its Alterations. 



or two inches down to one-eighth of an inch in diameter, but 

 generally bent. The coarser pseudomorphs of the second kind 

 are often of enormous size, as described under III. 



At the Barrus locality in Goshen, the Aglaite and Muscovite 

 are intercrystallized in similar ways. The laminse of the Musco- 

 vite also are continued into the gangue, and assist in producing 

 the strong adherence of the latter to the altered prisms. 



Genetic Relationships. — The nature of the chemical reactions 

 connected with the genesis of the pseudomorphs in Muscovite 

 and in Albite, may be understood from a consideration of the 

 following published analyses of the minerals from this region : 

 XVI— Muscovite from Goshen. S. G. 2.859. 



Analysis by 0. F. Eammelsberg (Zs. G., xix, 400). 

 XVII- — Muscovite from Goshen, rose-colored. 



Analysis by Mallet (Am. J. Sci., II, xxiii, 180, 1857). 

 XVIII— Albitc from Chesterfield. 



Analysis by Stromeyer (Untersuch., 300). 

 XIX — Albite from Chesterfield. 



Analysis by Laurent (Ann. Ch. Phys., lx). Both these 

 Albites were probably the Cleavelandite from Clark's 

 Ledge. 



Muscovite Albite 









XVI 



XVII 





XVIII 



XIX 



Fluorine, 







.52 











Silica, 







47.02 







70.68 



68.4 



Alumina, 







36.83 







19.80 



20.8 



Ferric Ox 



de, 





.51 





FeO, 



.11 



.1 



Manganous Oxide, 



1.05 











Magnesia, 







.26 











Lime, 













.23 



.2 



Lithia, 







i .30 



.64 









Soda, 







.99 





9.06 



10.5 



Potassa, 







9.80 



9.08 









Water, 







3.90 







99.88 







100.19 



100. 











Atomic Ratios. 











(Fe 



, Mn, Mg= 



=2K) 









H: K 







1.6 : 1 











H, K: Ah 



Ff 



.Si 



1.9 : 1 



: 2.1 



Na: Al 



:Si 2 : 



1 : 6 



