50 [Assembly 
To the former class, belong the iron and copper pyrites and the zinc 
blende which almost always accompany the galena, and to the latter, 
the various and interesting forms of calcareous spar, fluor and crystal- 
lized quartz, which are sometimes associated with them. Of the latter, 
large and beautiful specimens have been found accompanying the lead 
ore of the Shawangunk mountains, and the same minerals occur 
although not so perfectly developed, in the lead veins of Dutchess and 
Columbia counties. But in the northern counties, calcareous spar in the 
most diversified and beautiful forms, constitutes the principle matrix of 
the ore, while fluor spar, which in all other countries is so common an as- 
sociate of galena, is here of rare occurrence. 
The primary rocks in the northern and southern parts of the State 
agree in the frequency of the beds of limestone which they contain. 
These beds, whether they owe their origin to the agency of water or 
of fire, are of a white colour, often have a highly crystalline structure and 
contain various imbedded minerals, which in some cases so much im- 
pair the purity of the limestone as to render it unfit for the lime-burner. 
Sometimes these beds are composed of the carbonates of lime and 
magnesia usually known by the name of dolomite. A striking feature 
in the mineralogy of some of the northern counties is the variety and 
beauty of the crystallization of calcareous spar. These crystals are gen- 
erally found near the junction of the limestone with the granite or gneiss, 
or form the veins of spar which every where traverse them. The most 
interesting and beautiful specimens of this kind are to be found in the 
lead veins of Rossie, in the decomposed rocks at Ox-Bow and at Gou- 
verneur. Sometimes the crystals are of enormous size and have the 
transparency of Iceland spar. Indeed in no part of the State are these 
crystalline forms so finely developed or so abundantly diffused. 
In regard to the rarer minerals found in the white limestone group 
in the northern and southern parts of the State, there is also a simi- 
larity, while there are it is true, some points of difference. Serpen- 
tine of various shades, and often assuming a semi-crystalhne form is 
equally common in both, together with occasional crystals of mica, 
blades of plumbago, &c. There are also to be found in them horn- 
blende in all its varieties, pyroxene, scapolite, phosphate of lime, zir- 
con, sphene, tourmaline, garnet, brucite and spinelle. The two last 
named minerals, however, have heretofore been found in much less 
abundance in the north than in the south. Orange county is particularly 
richm localities of these interesting, and elsewhere rare minerals. 
