226 
DESCRIPTIVE MINERALOGY. 
Fig. 97. 
Flg ' i)6 ' At the Natural dam, about two miles from the village of 
Gouverneur, loose crystals of various sizes occur in a de¬ 
composed rock. Some of these are very large, but they are 
usually from half an inch to two inches in length. Many of 
them are single rhombohedrons with the contiguous acute 
edges replaced by broad tangent planes. Fig. 96. P on g 
about 143°. In some cases, three or four of the sides are 
similarly replaced. Two, three or more crystals are often 
grouped together by the opposite faces, presenting an imbri¬ 
cated appearance. Figs. 97 and 98 represent twin crystals 
which I have found at this locality, and the arrangement of 
which will be easily understood. It may be observed that 
the colour of the calcareous 
from the Natural dam is of¬ 
ten brown, and the surfaces 
of cleavage are bent like 
pearl spar. But here as at 
Oxbow in Jefferson, this va¬ 
riety constantly passes into 
the white, transparent and 
opaque kinds. They are 
probably all pure, or nearly 
pure carbonate of lime. 
In the town of Rossie, about a mile southeast of Oxbow in Jefferson county, there is a loca¬ 
lity not unlike that on the farm of Dr. Benton (see page 218). The crystals are similar in form, 
and are also found in a decomposed limestone. Transparent cleavages of considerable beauty 
have been obtained here, as well as those which are white and opaque, brown, yellow, rose and 
purple. Crystals of three or four inches in length occur, which are doubly terminated. Many 
of them are peculiar in having a white opaque coating on the surface, and some of them appear 
to have undergone a kind of dissection or solution, the whole exterior being studded with sec¬ 
tions of minute crystals. The appearance is not unlike that which is observed when an amor- 
pi s "• phous mass of alum is allowed to remain for some time in water. The 
most interesting crystalline form that I have observed here, is a compound 
one represented in Fig. 99. As in some of the crystals from Lockport, 
six of the edges are not well defined, the principal faces being only a little 
rounded. 
At the Parish ore bed in Gouverneur, geodes of calcareous spar are 
found in the specular iron ore ; some of which possess considerable beauty. 
The forms are the primary and the dodecaedre of Haiiy (Fig. 71). 
To the above localities, I may add the bank of Laidlaw lake, Rossie, 
where loose crystals have been found; and the town of Russel, where it 
is said to be of a reddish colour. 
