288 ANALYSES OF ROCKS AND MINERALS, 1880-1908. 
COOKEITE. 
From Pala, San Diego County, California. Analysis by W. T. Schaller. 
GI Oli uigos Gee seccaiet eembeeeeaen ss 6 vecmurce 35553: |) gO Qt 108s 2 ae sisi sexecicetinidae teaec se 61 
ANG Osho soi cu decd oases ee kee ieeeeRees cee sees 44.23 | HeO above 105°.............0.22 2. eee eee 13.57 
MnO wcacecce sevonceueumoukeeeensse sae trace. |) Pisses ccdeces! ame wes Mexnaesugies eeseaeness 1.46 
MgO: acnceumccmied Geese dieaecen EES trace 
Ca Oi sc seem eer eciseeeneeseerheeie Sse trace 100. 55 
TAO So tc ots leltaccromnsinmaen eee mba sma ae eee DET! i DACSS!.O si cjsra sha cioisicitis gist teste Mora Gs ER EaREoe 61 
Nag Oe aerwrecatesetiisce talcntrcinsrsnise cs tes eee 2.11 
Ke Oe ss ta peeetaeesaeys eeeessnceute aeons 31 99.94 
CRYOPHYLLITE. 
From Rockport, Massachusetts. Analyses by R. B. Riggs. Discussed by Clarke 
in Bull. 42. ; 
A. Brilliant, broadly foliated, blackish-green variety. 
B. Paler, dull green, less lustrous, probably somewhat altered. 
C. Granular, resembling chlorite. 
BIOTITE, 
A. From Merrow Ledge, Auburn, Maine. Black. Analysis by F. W. Clarke and 
R. B. Riggs. 
B. Bronze mica, Laurel Creek corundum mine, Rabun County, Georgia. Analysis 
by E. A. Schneider. The loss is due to undetermined volatile matter. 
C. Brown mica from the granite of the Yosemite Valley, California. Analysis by 
William Valentine. Described by Turner, Am. Jour. Sci., 4th ser., vol. 7, p. 294. 
D. Mica from quartz monzonite, Tioga road, southeast of Mount Hoffman, Mariposa 
County, California. Sp. gr., 3.05 at 21°. Analysis by W. F. Hillebrand. Described 
by Turner, loc. cit. 
E. Black mica from quartz monzonite. About 1 kilometer south of Bloods station, 
Alpine County, California. Analysis by William Valentine. Described by Turner, 
loc. cit. 
F. Reddish-brown mica from pyroxenic gneiss. North Fork of Mokelumne River, 
above mouth of Bear River, Amador County, California. Analysis by William Val- 
entine. Described by Turner, loc. cit. 
G. Biotite from the granite of Butte, Montana. See Weed, Jour. Geology, vol. 7, 
p. 737. Analysis by H. N. Stokes. 
H. Biotite from orthoclase gabbro, between Blue and Mud Lakes, Livingston 
quadrangle, Montana. See W. H. Emmons, Jour. Geol., vol. 16, p. 193. Analysis 
by G. Steiger. 
