SAPPHIRE IN UNITED STATF^S. 
109 
account of the color of the stones. The}^ are, for the most i)art, of a 
pale-green isli or greenish-yellow color, and do not connnand ;i very 
high price in the market. Occasionally ])iid< and yellow ones have 
,i.|,f 3een found that have cut good gems. Stones approaching a red or 
jlue color are, however, extremely rare. 
There are still a great many sapi)hircs in the gravels that have not 
been worked, but on account of their color it is rather doubtful 
whether under the most favorable conditions it wull i)ay to mine them. 
The cr3^stals from all these l)ars show the same development, and 
are prismatic in habit. The prism, a (1120), is always present, and 
is usually in combination with the base, v (0001), and the unit rhom- 
bohedron, /• (1011), as represented in fig. 16, A. Some of tlie crystals 
ave the prism very short and the rhombohedroii is Avanting, giving 
the crystal a very tabular appearance (fig. 10, B). A pyramid of the 
lecond order, n (2243), was observed on some of the crystals in addi- 
ion to the base and unit rhombohedroii, and is represented in fig. 
[6, C. 
The crystals are usually rough and more or less striated, so that no 
leasurement could be made upon the reflecting goniometer, but suf- 
(p 
A. B. a. 
Fig. 16. — Sapphire crystals from Missouri River bars, Montana. 
ficiently accurate measurements could be obtained with the contact 
- goniometer to identify the faces. 
The largest crystal that has been observed from an}^ of these bars 
,jl jwas one from Eldorado Bar that was nearly an inch long and three- 
1,1 pighths of an inch in diameter. 
f(i] A repeated growth was observed on some of these crystals, but not 
|in the variety of forms seen in the Cowee rubies (p. 101) and the Togo 
i,(l(iGulch sapphires (p. 113). Only one form of grow^th was observed. 
jJrepresented in fig. 16, A, which is a combination of the unit rhombo- 
,j|hedron and the base. 
Since the discovery and mining of sapphires from the Missouri 
River bars sapphires have been found at three other localities in Mon- 
tana — at Kock Creek, Granite County; at Cottonwood Creek, Deer- 
lodge County, and at Yogo Gulch, Fergus County. 
The first two localities are about 80 and 30 miles, respectively, 
southwest of those on the Missouri River, and the last one is about 80 
rici 
U 
