80 
GEOLOGY OF THE SECOND DISTRICT. 
for the furnace. This toughness may not be a constant character with the 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 mstances 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. 
3. 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 this latter color, it is extremely tender 
and quite lamellar, and soils the 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 of the whitest and purest soapstone is 
found interlaminated 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 
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 sienite 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¬ 
sary 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. 
Its relation to other rocks. —Sienite, besides being a constant associate of hornblende, 
appears very frequently as an injected rock, in the form of dykes, and is intertruded into 
