MINERALS, 
GEARKSUTITE. 
From St. Peters Dome, Pikes Peak district, Colorado. 
brandin Bull. 20. Analysis by W. F. Hillebrand. 
PROSOPITE. 
251 
Described by Cross and Hille- 
Two samples of prosopite have been analyzed by W. F. Hillebrand, as follows: 
A. From St. Peters Dome, Pikes Peak district, Colorado. Described by Cross and 
Hillebrand in Bull. 20. Sp. gr., 2.880 at 23°. Mean of four analyses. 
B. Pale green, massive variety, from the Dugway mining district, Tooele County, 
Utah. Sp. gr., 2.87 at 21° Described by Hillebrand in Bull. 167. 
a Including a little quartz; undetermined. 
TYSONITE, 
From Cheyenne Mountain, near Pikes Peak, Colorado. Analyzed by W. F. Hille- 
brand and described by him in Bull. 167. Corrected sp. gr., 6.14 at 28°. 
