DEPARTMENT OF GEOLOGY 
S5 
A collection of auriferous quartzes of Oregon and California. 
A series of gold and silver ores of Nevada. These are very 
diverse in appearance and from widely separated parts of the 
state. The Comstock lode ores are represented by some fifty 
specimens. 
A series of gold and silver ores from western Montana, in- 
cluding Butte and the several mining districts of eastern and 
southern Idaho. 
A very diversified series of ores of both gold and silver from 
Utah. These include the brilliantly colored ores of Mercur and 
the peculiar fossiliferous sandstone from Silver Reef. 
A collection of gold ores from the Black Hills, South Dakota, 
presents a good example of the great variety of gold ores which 
may occur in a limited area. Compare, for example, the ore 
from the Homestake mine with that from the Holy Terror, which 
again is wholly different from that of the Golden Reward mine. 
In Hall 79 may be seen ores of yet different characters from this 
region, some carrying tin, tungsten, etc. 
The gold and silver mining districts of Colorado are repre- 
sented by more than 500 specimens, grouped according to the 
mining districts in which they occur. The great variety of these 
ores is well illustrated. Cripple Creek gold ores, on account of 
their unusual character, are illustrated by numerous specimens 
both of the ore and the rocks in which it is found. 
A series of ores from New Mexico presents chiefly lead-silver 
ores, among which the galena from the Hillsboro region, and 
the “carbonate” lead-silver ore and galena of the Magdalena 
mountains, are prominent. Ores of other classes including 
those of silver-copper from the northern part of the territory and 
various types of gold-silver ores from the Gallinas mountains 
are also represented. 
The series from Arizona includes sufficient silver-copper and 
gold-copper ores to present somewhat the appearance of a col- 
lection of copper ores. With the ores from the Tombstone re- 
gion are a series of the rocks of the district among which the ores 
occur. 
The ores of the Appalachian mountains of Ontario, including 
Cobalt, and of Nova Scotia are installed in one series. They 
are, in general, except those from Ontario, gold ores with but 
little silver and consist of quartz or quartz and pyrite. These 
gold ores were the first exploited in the United States. They 
