220 
DESCRIPTIVE MINERALOGY. 
Fls - 70 - At Brownville, four miles from Watertown, perfect crystals 
have been found in the form of the equiaxe of Haiiy (Fig. 58); 
and the same with the edges rounded, forming lenticular crys¬ 
tals (Fig. 70). 
There remains still to be noticed a locality in the town of 
Wilna, about a mile northeast of Natural bridge. Crystals of 
calcareous spar are found in seams in the primary limestone. 
They are white, and exhibit a variety of forms, as the low 
six-sided prism, elongated dodecahedrons, and rhombohedrons 
with various truncation. They are, however, seldom sufficiently perfect for accurate mea¬ 
surement. In the same vicinity, there are large masses of this mineral so loosely aggregated 
that a blow of a hammer causes them to separate into rhombohedrons of various sizes. The 
smaller specimens are translucent, and have a delicate and beautiful blue tint. This colour is 
probably owing to oxide of iron; but if so, the quantity is too small to be easily detected by 
analysis. 
Lewis County. This county abounds in localities of calcareous spar, 
which afford a variety of interesting forms. It occurs in the Trenton 
limestone, and is often associated with galena, iron pyrites and fluor spar. 
The most common form is the dodecaedre of Haiiy (Fig. 62), which 
occurs at Leyden, Lowville and Martinsburgh. The prism, however, 
is often much compressed, as in the accompanying Fig. 71. At Low¬ 
ville, the calcareous spar is associated with iron pyrites and cubical 
crystals of fluor spar, in a vein on the banks of the creek near the falls. 
At Martinsburgh, the best crystals were obtained from the excavations that were made for 
lead ore, with which they are here often associated. In addition to the lenticular crystals 
which occur at this locality, are several modifications of the dodecaedre, some of which are 
represented in Figs. 72, 73, 74 and 75 : 
Fig. 72. 
Fig. 73. 
Fig. 74. 
Fig. 75. 
