254 DESCRIPTIVE MINERALOGY. 



Herkimek County. Brown and pearl spar, in white and 

 ^^' '^^' pearly crystals, are found in geodes in the calciferous sand- 



stone at Little-Falls, Middlcville, &;c. They are associated 

 with crystallized quartz and anthracite. The pearl spar has 

 ^ZZz^^(QQQ's?^!$6^ the crystals much bent, as in Fig. 127. 



Monroe County. In the limestone at Rochester and else- 

 ^XX^'-c^^iSy where in this county, fine specimens of pearl spar have been 



obtained. The accompanying minerals are calcareous spar, 

 snowy gypsum, and rarely fluor spar, celestine and zinc blende. 



Montgomery County. Brown or pearl spar is found with galena and calcareous spar, in a 

 vein in slate in the town of Root. 



New-York County. At Kingsbridge, dolomite occurs large grained, and sometimes with 

 indications of a foliated structure. It has been extensively used as a building material, and 

 for burning into lime. It is similar to the marble found in Westchester county. 



Niagara County. Pearl spar, associated with calcareous spar, selenite, sulphate of stron- 



tian, and rarely with fluor spar and zinc blende, is found in the fetid limestone at Lockport, 



Pj_^ j2g Niagara falls, and elsewhere in this county. At Lockport, 



where there are immense numbers of superb geodes of 



various sizes, the crystals are of a white colour, and some- 



^ / ' :p \. times with a delicate pink tinge. They are rhombohedrons, 



. ,, and have their surfaces much curved as in Fig. 127, with a 



P \ 7\. yy^ liigh pearly lustre. The specimens at Niagara falls are of 



a similar form, but are much less beautiful than those of 



Lockport. The twin crystals. Fig. 128, occur at both these 



localities. 



A specimen of pearl spar from Lockport, which I analyzed, contained 



Carbonate of lime, 59. 00 



Carbonate of magnesia, 39. 50 



Carbonate of iron, 1.50 



Oneida CouNTy. There is a locality of brown spar at Clinton, near the College ; but it is 

 not of much interest. 



Orange County. The limestone in the village of Warwick affords good specimens of 

 brown spar. This variety is also found a mile southeast of that village, and at Hampton, 

 six miles northeast of Newburgh. It also occurs at the Wilks mine in Monroe. 



Putnam County. The variety dolomite abounds in various parts of this county. On 

 Hustis' farm in Phillipstown, there is a stratum of the variety gurhofite. It is sometimes 

 snow-white, very fine grained and compact ; has a semi-opaline appearance, and a fracture 

 resembling porcelain. Its composition, according to my analysis, is as follows : 



Carbonate of lime, 66. 75 



Carbonate of magnesia, 26. 50 



Silica, 6. 75 



