GEOLOGY OF THE SECOND DISTRICT. 



for the furnace. This toughness may not be a constant character witli tlie ores embraced in 

 hornblende. 



This rock is associated with many other beds of ore in Moriah. The ores of Duane, in 

 Franklin county, belong also to it. In most of the instances cited, if not all, it is merely a 

 mass subordinate to gneiss. All the details which have been given of gneiss, as it regards 

 strike and inclination of the beds, apply to this rock. 



:i. Talc, or Steatite. 



This substance is readily distinguished by its soapy feel, and its extreme softness, being 

 easily scratched by the finger nail. Its colors are green, greenish white, and silvery white 

 without a tinge of green or any other color. When of thislatter color, it is extremely tender 

 and quite lamellar, and soils tlie fingers like chalk. It lies between the layers of gneiss or 

 hornblende. It is not at all abundant in the Second District. 



Localities. — Near the Belmont farm in Fowler, some ot the whitest and purest soapstone is 

 found interlaminatcd with gneiss. On the Oswegatchie in Dekalb, St. Lawrence county, it 

 occurs nearly as white as that at Fowler. Much of the rock called soapstone in this vicinity, 

 is rensselaerite, which is not so white and pearly, nor so soft as talc. For lining stoves, for 

 jambs, hearths, etc., either rock may be employed. 



' Soapstone has been employed as a paint, and forms for some purposes an article quite 

 valuable : it is used for giving body, and any color which is desired may be employed with 

 it. It is particularly useful in places where lead and other articles are exposed to the action 

 f of acids and other corroding agents. With silex it forms a fusible compound, -which may be 

 employed in pottery. But its common use, that of a fire-stone for hearths and furnaces, is 

 one of the most important. Hence it is an object to search for it among the slaty and schistose 

 varieties of gneiss. In conclusion, I would remark that steatite is far less abundant in the 

 formations of New-York, than in those of the Green Mountain ranges of Vermont. 



4. SlENITE. 



The term sienitc is applied to a stratified rock, composed of feldspar and hornblende. It 

 is always dark-colored, but less so than hornblende rock ; it is frequently grey, in which case 

 both the feldspar and hornblende are in a granular state. It frequently differs so little from 

 hornblende, that it is difficult to draw lines of distinction. For this reason, it is rarely neces- 

 sarj' to keep up the distinction which it has been usual to make between those rocks. They 

 certainly pass into each other, by the predominance of one or the other of its elements. In 

 the same bed, we may often find every variety which can be formed of these two minerals. 



lis relation to other rocks. — Sienitc, besides being a constant associate of hornblende, 

 appears very frequently as an injected rock, in the form of dykes, and is intertruded into 



