DISSEMINATED NATIVE COPPER IN HORNBLENDE. 
173 
line of dip disclosed the fact that its 
width increased. With this encour¬ 
agement, the vein at the base of the 
cliff was exposed. At this point the 
vein had increased to two feet in 
width. This encouragement led to 
the further exploration of the mine, 
which soon afterwards led to the dis¬ 
covery of immense masses of native 
Parallel masses of copper CO pper, some of which weighed fifty 
and rock, forming the vein. 11 ° 
or sixty tons, b rom the first discovery 
of these masses, the milling enterprise assumed a better aspect. 
The progress of discovery has kept pace with the labor and 
expenditure of capital; and now the mines of lake Superior 
take rank with the most productive mines of the world. The 
shipments of copper from Cliff mine have amounted to 1800 
tons per annum, containing from sixty-five to seventy per cent 
of pure copper. 
DISSEMINATED NATIVE COPPER IN HORNBLENDE. 
§ 104. In the southern counties in Virginia, native copper 
has been discovered which occurs in small pieces in hornblende, 
with epidote in combination. It shows no tendency to arrange 
itself in veins, but is distributed irregularly in masses from the 
size of a pigeon shot to an almond. This discovery of copper 
was made in Carrol county, Virginia, and it has been found 
over a region thirty miles long, the breadth of which is unde¬ 
termined, but not over, it is supposed, ten miles. 
It appears that the discovery, up to this time, is interesting to 
the geologist, rather than useful to the miner or capitalist. Its 
origin is no doubt coeval with that of the rock. The cabinet 
specimens which I have seen, bear a trappean aspect. 
