352 GEOLOGY OF THE SECOND DISTRICT. 



half a mile or more ; in some places the rensselaerite is black, and is traversed by seams oi 

 white satin spar. Near this farm, or upon the adjoining one south, it occurs in larger masses, 

 associated with primary limestone and quartz ; the latter is rose-red, and presents more of a 

 vitreous aspect than usual. 



Another locality is in Edwards, at the mine of specular oxide. This is white, mchnmg to 

 grey. This locality has furnished the material for inkstands, some thousands of which have 

 been manufactured by one individual. 



On the road from Edwards to Russel, this rock occurs in several large masses near the 

 road. 



Another locality of this substance is on the western side of the Oswegatchie, about half a 

 mile north of the village of Dekalb, near a bridge, and the rock is half or three-fourths of a 

 mile lontf. It is white, but less pure than at other places, in consequence of being mixed 

 with quartz. 



This rock is frequently intersected with veins of quartz. Sometimes the quartz is spread 

 smoothly over its surface, and in others dips down into its substance, checking it in various 

 directions, though without regularity. 



Rensselaerite occurs also in Hermon, Gouverneur, and in Canton. In the former place 

 arc large masses, which possess a crystalline structure throughout. In Canton, near the cop- 

 peras works, it may be found in small but distinct crystals. 



Origin of Rensselaerite. In the general account which I gave of the rocks of the Second 

 district, I advanced the opinion that rensselaerite belongs to that class of rocks which arc 

 supposed to have an igneous origin. All the phenomena connected with the mass, at the 

 different localities I have cited, go to sustain this opinion. It is associated with rocks of an 

 igneous character ; it is unstratified, and forms large irregular shaped masses, with no divi- 

 sional lines similar to those of gneiss or mica slate ; it is even rare to be able to distinguish 

 natural joints. We are able, therefore, to add another rock to the unstratified class or divi- 

 sion. It is analogous to serpentine in the mode in which it appears among other rocks ; but 

 it does not, like that substance, form with limestone a distinct aggregate. It is often found, 

 however, in distinct crystals in limestone, and in this respect it resembles hornblende and 

 pyroxene. 



Purposes to which it is adapted. In an economical point of view, rensselaerite is of some 

 importance. It may be used for a variety of small domestic articles, but it would be still 

 more valuable as a lining for stoves, grates, etc. It receives a good polish ; and as it is quite 

 tough, and at the same time soft, it may be turned in a lathe, or cut into a variety of articles 

 both ornamental and useful. 



Steatite or So.\pstone. 



This substance is much less common in the northern counties, than in the primary of New- 

 England. All the central ranges of the Green mountains abound in steatite, differing in 



