390 
DESCRIPTIVE MINERALOGY. 
exposure to the atmosphere. The hepatic variety is mentioned by Cleaveland as having been 
found in this county. 
St. Lawrence County. There are several localities in this county, where iron pyrites 
occurs both massive and crystallized. In the vicinity of Canton, there are extensive beds 
which may be advantageously employed in the -manufacture of copperas. 
The hepatic variety of this mineral has been found in the vicinity of Pope’s mill, associated 
with crystallized mica. It has a bronze-yellow colour, which tarnishes by exposure ; has a 
lamellar structure, and the laminae are easily separable. It is not magnetic. In its chemical 
characters, it agrees with the other varieties. 
The crystallized mineral is often associated with galena, numerous veins of which are known 
to occur in various parts of this county. The most interesting specimens have heretofore been 
found at the Rossie vein. The colours are bronze and pinchbeck- 
yellow, sometimes yellowish white. The lustre and finish of the 
crystals are frequently very high, and their perfection does not appear 
to be impaired by exposure. Among the forms which have been no¬ 
ticed here, are the cube (Fig. 448); the cube with the edges replaced 
by tangent planes, sometimes so slightly as to be scarcely perceptible, 
Fig. 455 ; the cube with the angles and edges all replaced by planes, as 
in Figs. 454, 456, 457 and 458 ; together with the triglyphe of Haiiy, 
Fig. 455. 
"X- P 
! *' XX 
1 v 
c 
p 
1 
.. 
.... 
—J 
Fig. 456. Fig. 457. Fig. 458. Fig. 459. 
Fig. 459, in which the threefold cleavage is distinctly indicated by the strife. P on o 144° 44 / 8"; 
o on o' or o" 146° 26' 33" ; P on / or/' 143° 18" 2"; P on d 152° 15' 52" ; d on/ 157° 
47' 33" ( Haiiy). 
Fig. 460. 
Schoharie County. About a mile west of Schoharie court-house, 
iron pyrites occurs in great abundance in single crystals and groups, 
in a decomposed clayey green shale. The colour is from brass 
yellow to reddish brown. Small but very perfect cubes are found 
in a kind of dark-coloured cellular heavy spar. In the slate, the 
crystals generally have the form of the dodecaedre of Haiiy (Fig. 
450). They are sometimes from half to three-quarters of an inch in 
diameter. The forms represented in Fig. 455, 458 and 459, and the 
compound one, Fig. 460, also occur at this locality. 
