83 
HALL 79. 
COPPER, ZINC, TIN, ANTIMONY, MERCURY, 
NICKEL, IRON AND riANQANESE, 
The collections in this hall comprise the typical copper, zinc, 
tin, antimony, mercury, nickel, iron, and manganese ores, and the 
minerals of economic value that commonly enter into the compo- 
sition of these. There are also to be seen products resulting 
from the treatment of some of the ores, maps illustrating localities 
where they are obtained and charts showing processes of extrac- 
tion of the metals. 
Under each group are placed first, type specimens of the dif- 
ferent ores of the metal arranged in order of their richness; then 
specimens of ores which illustrate the different localities produc- 
ing them, these being arranged in geographical order, passing 
from California eastward. Specimen labels show the mineral of 
the ore and the amount of metal produced from them, where this 
is known. It should be remembered that many of the ores pro- 
duce more than one metal, in which case the specimen is placed 
in the group of the predominating metal. 
COPPER. 
Case 1. — The copper bearing minerals, arranged in order of 
their richness; the native metal ^ this being the character of most 
of the ore from the Lake Superior mines ; the red oxide, cuprite, 83 
per cent, of copper; the black oxide, tenorite, 8o per cent.; the 
black sulphide, chalcocite, 8o per cent.; the green carbonate, 
malachite, the blue carbonate, azurite, 55 per cent.; 
the purple sulphide, bornite, 55 per cent.; the gray sulphide, 
tetrahedrite, about 50 percent., the bluish green silicate, chryso- 
colla, 36 per cent.; and the brass yellow sulphide, chalcopyrite, 
34 per cent. 
Cases 2, 3, 4 and. 3. — Copper ores from different mines 
of the world arranged in geographical order. Notable among 
them are a series from the Rammelsberg mines, Germany, show- 
ing the change in character of the ores in different parts of the 
