306 
GEOLOGY OF NORTH CAROLINA. 
Diamond. 
Dr. Gen th has given all that is known on the subject of the occurrence 
of diamonds in North Carolina on p. 57 of the Appendix. All the spe- 
cimens hitherto found, were discovered by accident, and in washing for 
gold. Doubtless an intelligent search, by persona trained to recognize 
the gem in the rough state would have brought to light scores of them 
in the extensive gold diggings of the state. 
Agate. 
Rough specimens of this form of quartz are very common, for ex- 
ample, in Cabarrus, near Harrisburg and near Concord, and in Mecklen- 
burg; and occasionally a handsome gem has been found amongst them ; 
but a year or two ago some very tine specimens of moss-agate were dis- 
covered near Hillsboro, which were at last accounts in the hands of Col. 
Whitford. 
Opal. 
A number of gems of this species have been found in the state. 
Within the last twelve months a large number have been picked up in- 
Concord, Cabarrus county, some of them of much beauty and high market 
value. 
SECTION Y. MISCELLANEOUS. 
Mineral Waters. 
Both Chalybeate and Sulphur waters are of common occurrence in the 
tate and in all sections of it, the former eminently so. Alum waters 
are also of frequent occurrence. In the eastern section, the abundance 
of peat and muck insures the prevalence of carbonated waters, which 
are continually dissolving the iron oxides from the ferruginous Quater- 
nary earths, and in their issue in springs at the foot of the slopes and in 
the ravines, they come charged with this element, which is deposited in 
a flocculent ochreous precipitate, along the course of the streams. In the 
granitic and slaty regions of the middle and west, the presence of iron 
and alum is due to the decomposition of the iron pyrites, so- widely dif- 
fused in the gneisses, granites and slates. 
