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southeast. The vein, though various in character, and somewhat 

 difficult to describe, owing to the imperfectly developed nature of 

 its minerals, and their complete interfusion, may be characterized 

 as consisting, in the main, oimica in large excess, quartz, carbonate 

 of lime, felspar, and augite. It contains spinelle, sapphire, and 

 green talc, besides several other minerals less distinctly crystal- 

 lized. 



When we consider the highly micaceous character of the adja- 

 cent gneiss rock, through which the matter of the vein must have 

 passed in reaching the surface, and the abundance of the mica, 

 especially of the brilliant golden variety, found so plentifully not 

 only in it, but in the adjacent parts of the altered limestone, we 

 cannot resist the impression, that a portion of the primary strata 

 along the sides of the dike, have been melted and incorporated 

 into it, floating, in combination with the other materials, to the 

 surface. 



Immediately upon the western side of this curious vein, and 

 ranging along the base of the hill, occurs the narrow belt of 

 altered limestone. The gradation of change which here exists 

 between the blue and earthy limestone, and the white crystalline 

 rhombic spar, is distinctly traceable as we approach the igneous 

 dike. In a breadth not exceeding fifty feet, we discover every 

 degree of modification which the rock can undergo by heat. The 

 first intimation which the limestone gives us of its having been 

 subjected to the igneous agency, is its passage from the ordinary 

 earthy texture to a subcrystalline one. We next behold a slight 

 change of colour to a lighter tint of blue, and, at this stage of 

 alteration, we notice the first developement of the graphite, as yet 

 seen only in small but very brilliant scales, which are oftentimes 

 hexagonal. Very soon the mass becomes mottled with white, 

 minutely granular carbonate of Hme, the spangles of graphite 

 growing progressively larger. Approaching still nearer to the 

 dike, the whole rock assumes the white sparry character, and 

 contains, near the line of contact, besides the graphite, several of 

 the numerous crystalline minerals of the vein itself. So completely 

 has the injected matter of the vein been mingled, in many places? 

 with the fused substance of the limestone, that no distinct line of 

 demarcation is discernible between them. 



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