﻿356 



JB. W. Clarice — Liihia Micas. 



mon granular variety, secondly of the border upon muscovite, 

 and finally of the latter mineral from the center of the second 

 specimen. The muscovite analysis came oat as follows : 



Si0 2 



__. 44-48 



Na 2 



. 2-41 



Al 2 3 --~ 



_.„ 35-70 



K 2 



. 9-77 



Fe 2 3 ---- 



... 1-09 



H 2 



. 5*50 



FeO...._ 



.__ 1-07 



F 



. -72 



MnO 



. . trace 









CaO 



•10 





100-84 



MgO 



trace 



Less oxygen 



•30 



LiO 



trace 





100-54 



About these results there is nothing unusual. 



For convenience the analyses of lepidolite, all by Mr. Riggs, 

 may be given in one table. The water in every case was 

 determined directly by means of the Grooch tubulated crucible, 

 and most of the lithia separations were effected by a new pro- 

 cess, lately devised in this laboratory by Dr. F. A. Grooch, and 

 shortly to be published in full. In the Auburn and Norway 

 lepidolites, however, the old phosphate method was used. The 

 fluorine estimations were all by the Berzelian process. In the 

 figures given for (KRbCs) 2 0, we have actual determinations 

 based upon the amount of chlorine in the mixed chlorides, and 

 not a mere computation as K 2 from the weight of the chloro- 

 platinates. All important estimations were checked in dupli- 

 cate, and the table of results represents mean values. Seven 

 analyses were made, as follows : 



Analyses of Lepidolite. 





A. 

 Purple. 

 Kumford. 



B. 



Foliated. 

 Paris. 



c. 



Granular. 

 Hebron. 



D. 



Border. 

 Auburn. 



E. 

 Granular. 

 Auburn. 



p. 



White. 

 Norway. 



G. 



Brown. 



Norway. 



Si0 2 



51*52 



50-92 



48-80 



49-62 



51-11 



49-52 



50-17 



A1 2 3 



25-96 



24-99 



28-30 



27-30 



25-26 



28-80 



25-40 



Fe 2 3 



•31 



•30 



•29 



•31 



•20 



•40 



.87 



FeO 



undet 



•23 



•09 



•07 



•07 



•24 



•45 



MnO 



•20 



trace 



•08 



•55 



•17 



•07 



•23 



CaO 



•16 



trace 



•10 







•12 



•13 



undet 



MgO 



•02 



trace 



•07 







•01 



•02 



undet 



Li 2 



490 



4-20 



4-49 



4-34 



4-98 



3-87 



4-03 



Na 2 



1-06 



2-11 



•74 



2-17 



1-43 



•13^ 



- 13.40 



(KRbCs) 2 C 

 H 2 



> 11-01 



11-38 



12-21 



11-19 



12-25 



12-63 



•95 



1-96 



1-73 



1-52 



•94 



1-72 



2-02 



F 



5-80 



6-29 

 102-38 



4-96 



101-86 



5-45 

 102*52 



6-57 



5-18 



5-05 





101-89 



103-11 



102-71 



101-62 



Less oxyge 



l 2-44 

 99*45 



2-64 



2-02 



99-84 



2-29 



2-76 

 100-35 



2-18 

 100-53 



2-13 





99-74 



100-23 



99-49 



As regards cassium and rubidium the Maine lepidolites offer 

 some points of difference. In the Rumford material an or- 

 dinary analysis shows neither ; but a special examination upon 



