48 Reéxamination of American Minerals. 
These will be seen to correspond with the analyses (1, 2) of 
Rhodophyllite by Dr. Genth, and the analysis of rhodochrome (3) — 
and chrome chlorite (4), by Hermann. 
Bi. Ab. Fe Sr. Ni oMgvy Galina K 
oa qaa 
L Texas, Pa. 33°41 trace 35°86 trace O28 O10 12°79 
2. 2°98 .. 11 i a 6°85 trace 35°22 trace O28. 010 18:12 
3.L.1 84°64 1050 200 5°50 3547 —— ——- — 1203 
4, sy , 31°82 re. 10 406 0-90 25. $6:24..———.. =~  —— 278 
Dr. Genth gives the same formula minus one ape of water. 
forms us that he observed a like variation in the specimens he 
examined. he chrome-chlorite examined by Hermann was un- 
doubtedly one of the light colored varieties. 
Nickel as well as lime is found in some specimens, but both 
are impurities ; the nickel is due to small particles of sulphuret of 
nickel which occurs at the same locality, and in many instances 
iron et from the ee of this aye icet 
. H. Garrett* has rece 'y Given an analysis of this min- 
al. " His results differ satay rom those obtained above. 
20. Cummingtonite—a Hornblende. 
This mineral was described by Dewey,t and analyzed by 
Muir.f{ The latter obtained for its composition, 
Si Fe Mn Na - H 
5654 21°67 7-80 844 3189763 
Authentic specimens for examination were procured from the 
Lederer collection in Yale College. Its structure is fibrous, re- 
sembling we ah lustre silky; color ash gray. It occuls 
in mica slate at Cummington, Mass. 
Two analyses gave : 
ili 51-09 : 5074 
Alumina, : : 95 i i 
Protoxyd of iron, 82-07 ‘ 83:14 
Magnes ‘ 10-29 : 10°31 
Manganese, . | 1:50 P 77 
Lime, trace . trace 
Soda, : ; 5 : 
Potash, trace : — 
Water, - ‘ r 3:04 
99°69 10043 
* This Journal, May, 1853, This Journal, [1] viii, 59. 
} Thomson's Min, 1, 493. y Ar? 
