218 



DESCRIPTIVE MINERALOGY. 



Fig. 65. 



Greene County. Large but imperfect crystals are found in veins in the limestone on the 



Catskill and Canajoharie railroad, about 

 *  two miles from the village of Catskill, from 



which, however, fine cleavages can be ob- 

 tained. They are sometimes transparent, 

 but are usually opaque and white. Near 

 this locality there are smaller but more 

 perfect crystals, having the form of the 

 equiaxe of Haiiy (Fig. 58), and also the 

 modifications. Fig. 63 and Fig. 64. 

 Small crystals having the primary form are found associated with crys- 

 tallized quartz in fissures in the slate, at Diamond hill, near the vil- 

 lage of Catskill. They sometimes have their edges and angles rounded, 

 similar to those which are observed in Albany and Schoharie counties. 

 The crystals not unfrequently assume the form of an oblique rhombic 

 prism, which is twice as long as it is broad (Fig. 65). Minute crystals of 

 the form represented in Fig. 63, also occur. The prisms of quartz inter- 

 mixed with the calcareous spar at this locality are often long and slender, 

 and have their points coated with carbonate of lime. 



Hamilton County. According to Dr. Emmons, blue calcareous spar 

 occurs on Long lake, in this county. I have met with a similar variety 

 in Lewis county, which I shall notice in its proper place. 



Herkimer County. There is a fine locality of calcareous spar about a mile south of Little- 

 Falls. In the bed of a small stream, and in the blue limestone which rests upon the calcife- 

 rous sandrock, there is a vein of some width, which is entirely made up of the crystallized 

 spar. The crystals are white, and their usual forms are the equiaxe of Haiiy (Fig. 58), and 

 the modification (Fig. 63). They are sometimes from two to three inches in diameter. 



At Middleville, low six-sided crystals, similar to that represented in Fig. 64, and sometimes 

 of very large size, are found in the cavities of calcareous sandrock, associated with anthracite, 

 and the beautiful crystals of limpid quartz for which this locality is so justly celebrated. 



Jefferson County. This and the adjoining county, St. Lawrence, contain numerous loca- 

 lities of calcareous spar, which are of great interest. Indeed, there is probably no part of 

 the world in which the crystalline forms of this mineral exhibit greater variety or beauty, or 

 where crystals of such enormous size have been found. 



By far the most interesting locality in this county, is that on the lands of Dr. Benton, near 

 the village of Oxbow. Large crystals have here been found in the soil, or rather in a decom- 

 posed limestone, which by cleavage often furnish beautiful rhombohedrons nearly transparent 

 and colourless, or with a delicate tint of rose or purple, and which possess the property of double 

 refraction. Sometimes they are white and opaque ; at others, they have a brownish colour, 

 and have their cleavage planes bent like the crystals of pearl spar ; but this variety constantly 



