70 ANALYSES OF ROCKS AND MINERALS, 1880—1908. 
5. MISCELLANEOUS ROCKS. 
First group: Collected and investigated by Arnold Hague and J. P. Iddings. 
A. Black obsidian, Obsidian Cliff. Liparose. Described by Iddings, 7th Ann. 
Contains microlites of augite and magnetite, with traces of quartz and feldspar. 
Analysis by J. E. Whitfield, record No. 224. 
B. Red obsidian, Obsidian Cliff. Alaskose. Described by Iddings, 7th Ann. 
Like A, with ferric oxide replacing magnetite. Analysis by Whitfield, No. 223. 
C. Obsidian, east of Willow Park. Lassenose. Black and opaque. Described by 
Iddings, Bull. Philos. Soc. Washington, vol. 12, p. 204. Analysis by Whitfield, 
No. 222. , 
D. Lithoidite, Obsidian Cliff. Lassenose. Described hy Iddings, Bull. 150, p. 
153. Contains quartz and sanidine, with a little magnetite and augite. Analysis 
by Whitfield, No. 425. P. R. C. 62. 
E. Rhyolite, Upper Geyser Basin. Lzparose. See Iddings, Bull. Philos. Soc. 
Washington, vol. 12, p. 204. Analysis by F. A. Gooch, record No. 114. 
F. Rhyolite, Tower Creek. Toscanose. See Iddings, Bull. Philos. Soc. Washing- 
ton, vol. 12, p. 204. Analysis by Gooch, No. 115. 
G. Rhyolite, “Great Paint Pots.’’ Liparose. Analysis by Gooch, No. 113. 
H. Rhyolite, ‘Elephants Back.’’ Porphyritic obsidian. Tchamose. Analysis 
by Whitfield, No. 423. Reported by Iddings as containing quartz, sanidine, and a 
little augite and magnetite, in a glassy, microlitic groundmass. 
I. Rhyolite, Mount Sheridan. Tehamose. Composition reported by Iddings as 
quartz and sanidine, with a little magnetite and augite. Analysis by Whitfield, No. 
426, 
