PKATT.l CORUNDUM GEMS. 51 
were obtained. Of these aboul L2, 000 carats are lit for cutting. In 
color they are much more varied than those from the Missouri River 
bars, and the prevailing color, which is greenish to bluish green, is 
deeper. No deep-blue sapphires like the oriental si ones have been 
found, but paler blue ones have been obtained, from which very- 
handsome sapphires 2 or 3 carats in weight have been cut. Some 
of the finest yellow sapphires (oriental topaz) that I have ever seen 
have been found at Rock Creek. One of these weighed close to 2 
carats when cut. Pale green and bluish green are among the common 
stones, sonu 1 cutting gems of 5 to 8 carats in weight. A number of 
beautiful pink sapphires have also been found. 
Few red and ruby-colored crystals have been found and none that 
would cut a gem over a twelfth of a carat in weight. These colors are 
extremely rare in the Montana sapphire deposits. 
The crystals and fragments of sapphires that are found in these 
gravels do not show as much abrasion as those from the Missouri 
River, probably because they have been carried a shorter distance 
from where they originated. 
In habit the crystals are very similar to those already described 
from the Missouri River, and fig. 9 will also illustrate very well the 
character of the Rock Creek crystals. One type that is very notice- 
able is a short prismatic crystal, whose diameter nearly equals its 
length. A parallel growth on the basal plane is only occasionally 
observed, and is composed of the basal plane and anil rhombohedron. 
No sapphires have as yet been found in situ, but a few have been 
found in the gravels that were embedded in the original matrix. Mr. 
Knnfh, to whom I showed a specimen of the andesite containing sap- 
phires from French Bar, said that it very closely resembled the small 
fragments of rock carrying sapphires that he had found at Rock 
Creek. It is not at all improbable that these sapphires originated 
in the same type of rock as those of the Missouri River and that 
small dikes of andesite will be found in the divide between Myers, 
Cold, and Quartz creeks. A very few sapphires have been found on 
Quartz Creek. 
While the sapphire gems from Rock Creek do not command so high 
a price as the ruby and the deep-blue sapphires, and are regarded more 
as fancy stones, they are coming to be quite highly prized by many 
who are acquainted with them. As yet but few of the Rock Creek 
sapphires have been put on the market except locally at Helena, and 
it seems to me that it can be confidently predicted that these sapphires 
will become important in the jewelry trade when they are once known. 
COTTONWOOD CREEK SAPPHIRES. 
The sapphire deposits on Cottonwood Creek are in Deerlodge County, 
about 30 miles southwest of Helena and 10 miles east of Deerlodge, 
the county seat. There has not been a great deal of work done on 
