6s 
COPPER. 
Entering the Hall from the West Dome, the copper ores are 
to the left. They fill six wall cases and the two adjacent floor 
cases. The first wall case contains the copper-bearing minerals,, 
arranged in order of their richness; the native metal; the red 
oyiide:, cuprite, 88 per cent, of copper; the black oxide, tenorite, 80 
per cent., the black sulphide, chalcocite, 80 per cent, the blue 
sulphide, cocellite, 66.4 per cent.; the green carbonate, mala- 
chite, 57 per cent. ; the blue carbonate, az^irite, 55 per cent. ; the 
purple sulphide, bornite, 55 per cent. ; the gray sulphantimonide,. 
tetrahednte, about 50 per cent.; the bluish green silicate, chryso- 
colla, 36 per cent ; and the brass yellow sulphide, chalcopyrite,. 
34 per cent 
On the lower shelves of this case is a collection of the cop- 
per ores of the Appalachian Mountains. 
-The following wall case contains a collection of native cop- 
per and silver and the minerals which are associated with the 
copper of Northern Michigan. The crystallized copper and the 
calcites are especially noteworthy. 
The two following wall cases, in the northwest corner, con- 
tain copper ores from the Western United States, chiefly the 
Rocky Mountains. The copper ores of this region usually carry 
gold or silver, and many localities corresponding to a very con- 
siderable output of copper ore are represented among the gold 
ores of Hall 72. 
Immediately in front of these cases are two table cases with 
large specimens of the copper ore from Keweenaw Point, North- 
ern Michigan. In these ores the copper exists as nodules of free 
metal, which may be seen projecting from the enclosing rock 
matrix. With these are placed large specimens of Arizona ore 
of a similar nature. 
Returning to the wall cases the visitor may inspect next 
foreign copper ores contained in two cases. 
Those of Great Britain, chiefly from Cornwall and Wales, 
have been worked from the time of the Phoenicians. Those 
from Germany, which also represent mines of great antiquity, 
should be studied in connection with zinc, silver and lead ores 
from the same mines. 
4 
