410 EEPORT UNITED STATES GEOLOGICAL SURVEY. 



tained; specimens kept three or four years showing it as well as the 

 fresh specimens. 



ANALYSIS. 



(The specimen is m convoluted layers, with bronze-colored surfaces ; the bronze layers 

 alternate with whitish ones. The powder is fawn-colored. Hardness, 5.5.) 



Per cent. 



Silica 83.1 



Aluminum and iron sesquioxides 1.2 



Organic matter and water 13. 6 



97.9 



On heating to 212° F. the powder loses 5 per cent. ; a high heat causes 

 it to turn gray and give out a distinct odor of nitrogenous organic 

 matter. The iron and aluminum appear to be in union with this or- 

 ganic matter. 



Heart Lake Geyser Basin. 



The analyses, three in number, of specimens from this basin are the 

 only ones published up to the present time. They are the following : 



Rustic Geyser. — The specimen is an oval, or egg-shaped, pebble from 

 the outer basin of the Eustic Geyser. 



ANALYSIS. 



(Color, chalky- white on surface, porcelain-like inside; fracture irregularly conch oidal; 



hardness, 5.5.) 



Per cent. 



Silica 90.0 



Alumina and iron oxides 2.6 



Lime 1.6 



Water .5.0 



99.2 



Busfic Geyser. — Specimen from the edge of the geyser, when fresh. 

 This geyserite was translucent, resembling rock-candy in appearance 

 more than anything else. When dry, however, it became opaque and 

 white. 



ANALY'SIS. 



(Hardness, 5.5 to 6.) 



Per cent. 



Silica.... 87.3 



Water 10.3 



Aluminum and iron oxides 2.2 



99.8 



Deluge Geyser. — This specimen is from the outer basin of the geyser, 

 and is a light-pinkish laminated deposit, with rosette-like projections 

 or nodules on the surface. 



ANALYSIS. 



(Hardness, 5.) 



Per cent 



Silica 89.00 



Water 8.00 



Lime i 



Iron > undetermined.. 



Aluminum S • 



97. 00 



In the following table I have endeavored to present all the anlyses of 

 the Yellowstone geyserites that I could find. There are included sev- 

 eral analyses of Nevada deposits made by Mr. Woodward, taken from 

 the reports of the Survey of the Fortieth Parallel. Following this table 

 are tables of the New Zealand and Iceland geyserites. 



