174 
AMERICAN GEOLOGY. 
VITREOUS OR GRAY COPPER ORE. 
§ 105. In North Carolina, Chatham county, several veins of 
copper have been discovered, having at the outcrop of the vein 
and for fifteen or twenty feet more, gray copper; but it gives 
place to the yellow sulphuret sooner or later. There is nothing 
peculiar in the structure of the veins which carry gray copper. 
It is worthy of remark that it is massive, and that it is proba¬ 
bly an altered yellow sulphuret. 
The gray copper of Bristol, Conn., is associated with the 
yellow sulphuret and sulphuret of iron. It is remarkable for its 
fine crystals of gray copper. 
The red sandstone of Connecticut and New Jersey contains 
the carbonates, sulphurets, red oxide and blue sulphuret of cop¬ 
per. The locality at Simsbury, Conn., was known in the time of 
the revolution. Those of New Jersey appear, many of them, 
to be exhausted. Mining operations have been prosecuted at 
Somerville, Woodbridge and Farmington. As the efforts to 
obtain good veins of good mines of copper have signally failed, 
it is a matter of interest to determine the causes of these fail¬ 
ures. Prof. Rodgers, who has investigated the question very 
carefully, came to the conclusion that veins do not exist—that 
the copper occurs in proximity to the trap, and without vein¬ 
stone or mixture of other metalliferous matter, but in ramifying 
strings or bunches, which are more or less blended with the 
adjacent rock. At the Schuyler mine, the sulphuret and carbon¬ 
ate occur in a sandstone twenty or thirty feet thick, in which 
it is imbedded and forms a band which traverses the layer in a 
series of offsets or steps, and which has been pursued to the 
depth of 212 feet below the surface. The phenomena which 
bear upon the origin of the copper ore of the sandstone, seem 
to favor the view that it was sublimed through shrinkage 
cracks, or imperfectly formed fissures, and which also pene¬ 
trated more or less between the layers and into the porous sub¬ 
stance of the sandstone. 
