452 S. Weidman — Irvingite, a New Variety of Lithia-mica. 



Analysis of the lithia-mica, Irvingite. 



Analysis Molecular ratios 



SiO„ 57-22 954 



TiO„ 0-14 2 



A1„0 3 18-38 180 



Fe"„0 3 0-32 2 



FeO 0-53 8 



MgO 0-09 



CaO 0-20 3 



K„0 9-12 96 



Na„0 5-14 83 



Li 2 4-46 149 



F 4-58 120 



H„0 at 110°- 0-42 



H'O at red heat 1-24 69 



101-84 

 Less 0=F 1-93 



99-91 



In the following table the analysis of this lithia-mica is com- 

 pared with that of a representee analysis of lepidolite from 

 Rumford, Me., and of zinnwaldite from Zinnwald, Bohemia, 

 and with that of cryophyllite and polylithionite. 



Analyses of varieties of lithia-mica. 



1 2 2a 3 



SiO„ - 57-22 59-25 58'68 51-52 



A1 3 _-- .- 18-38 12-57 10-24 25-96 



Fe 2 3 0-32 4-02 0*31 



FeO 0-53 0-93 



MnO trace 0-31 0-20 



MgO 0-09 



CaO 0-20 0-1S 



K„0 9-12 5-37 11-05 11-01 



Na 2 5-14 7-63 1-61 1-06 



Li 2 4-46 9-04 8-24 4'90 



H 2 at 110°- .. 0-42 



H„0 at 110°+ -- 1-24 0-95 



F 4-58 7-32 8-16 5'80 6"78 7"62 



TiO„ 0-14 



4 



5 



51-96 



46-44 



16-89 



21-84 



2-63 



1-41 



6-32 



10-06 



0-24 



1-89 



0-15 





10-70 



10-58 



0-87 



0-54 



4-87 



3-36 



1-31 





Total 101-84 102-11 101-89 102-73 103-74 



Less = F 1-93 2-44 2'86 



99-91 98-87 99-45 99-87 



