on Utah, California and Nevada. 133 
marked reactions. It is highly improbable but that ilmenite 
among the frequently recurring factors of the gravel mass. 
11. Diamonds in California.—About twenty well-formed crys- 
amined weighs about 2} carats, and is of a faint yellowish 
color, with curved faces, and the form of fig. 58, in Dana's 
Mineralogy. Some of these stones were of a pure water, and 
ave been cut and set as gems. ° 
12. Sands of the Arizona Desert.—The search for “ diamonds, 
“rubies,” and “emeralds” in 1872, led to the sending of seve- 
ral expeditions into Arizona and southern Nevada. I have 
had, by the kindness of Mr. Geo. A. Treadwell, an opportunity 
of examining a portion of the findings of one of these parties, 
which explored a region about eighty-five miles northwest of 
Fort Defiance in Arizona. The region is described as one of 
porphyritic and other eruptive rocks. The “rubies” are gar- 
hets, some of very fine color and good size, but whether pyrope 
or common garnet, an analysis only can determine. m 
them, cut in San Francisco, which I have seen, compare well 
ite variety 
op yroxene, fluorite (white), magnetite, ilmenite, oligoclase 
and jasper. 
