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occasionally into fine. The colour of the Labradorite is a smoke gray, 
of different shades, in different specimens, generally opake, but often 
translucent, when the lamina are no more than h of an inch in thick- 
ness. In the most perfect specimens there are two reflections of colour, 
a blue and a gTeen, the one appearing in one direction from the face of 
cleaveage, the other, from another. The bronzed, or copper coloured 
reflections, appear in pieces, which are weathered. It will not be useful 
to describe all the varieties of colour, which this single species presents. 
It is sufficient to say, that they are extremely numerous, and frequently 
of surpassing beauty. The polished pieces form gems highly esteemed 
in jewellery, which certainly have this recommendation, that they can- 
not be imitated, a fact which can scarcely be stated of any other gem. 
From these remarks, the general character of the rock may be gathered. 
I shall now speak of its extent. The first appearance of the Hypers- 
thene rock, is in the north part of Schroon, on the State road. This is 
its southeastern limit. The eastern boundary extends from this point, 
north northeast through Moriah, passing about three miles east of West 
Moriah village, and onwards through West Port, Essex, Willsborough, 
and terminating at Port Kent. The northwest boundary lies along the 
Ausable, and may be traced to its source, and onwards in a southwest- 
erly direction, to the west part of Newcomb. The Primary rocks, pe- 
culiar to St. Lawrence county, as gniess, hornblende and limestone, ex- 
tend eastwardly as far as Newcomb. Gniess, accompanied by the same 
rocks, lie along the southeastern side of the Hypersthene rock, as in a 
part of Schroon, Crown Point, and the eastern part of Moriah. The 
breadth east and west of this Hypersthene formation cannot be less than 
thirty miles, and in length it extends diagonally across the whole coun- 
ty from Port Kent to Minerva. There is, probably, therefore, in the 
county of Essex, one af the most extensive primary formations in the 
whole State; and perhaps, there is no rock, or no single rock, in one 
Continuous surface, so great as this in New-York. 
The next inquiry, in relation to this rock is, has it any value as a 
building stone. In answer to this question, I have no hesitation in say- 
ing, that at many localities it will furnish the finest material for build- 
ing, of all the family of granites. In the town of Jay, for example, 
there are some of the finest samples of this variety of granite I have 
ever seen. It is not, however, so much as an outside building material, I 
wish to call the attention of the public, it is as an ornamental article for 
tables, chimney pieces, &c., and for this service, I consider it best adapted 
and of the most value. Like other varieties of granite, it may be split 
into rectangular pieces of any size, and these may be sawn, as I have 
