blende,
greenish augite, and yellowish felspar; all, except the felspar,
presenting a crystalline structure; it is also composed only of augite
and felspar.
The
name of the rock sienite was originally derived from Syene, in Upper
Egypt, from whence the first specimen was procured ; it was examined
and identified by Werner; many of the Egyptian monuments, such as
Cleopatra's Needle, and Poinpey's Pillar, were obtained from there.
There
are valuable quarries of sienite in abundance in the State of New York.
It is a durable and beautiful stone, and may be quarried in lai'ge
blocks, but on account of its great hardness requires much labor to
dress it.
Along
the North River there are many localities: Anthony's Nose, or Anthony
s Face, which is a mountain in the northwest corner of Putnam county,
opposite Fort Montgomery. It is called so in consequence of the profile
bearing a rude resemblance to the human face, that may be seen in one
position, when passing it; but on account of its steepness, being five
hundred feet in height, it is more generally called Breakneck Mountain.
Here is the granitic sienite. It is composed of a darkish-gray colored
felspar, with a little black hornblende.
In
Peekskill bay, on the Hudson river, and the adjoining hills for five
miles in length, very valuable quarries of this fine rock may be
quarried.
The
sienite rock of the Highlands is very extensive; such as the Target
rock on Constitution Island, opposite West Point, and all along the
slopes of the mountains in the Highlands, there are boulders and blocks
of this valuable and useful rock.
Fort Putnam, near West Point, and the base of Butter Hill, four miles north of West Point, are composed of sienite.
When it was ascertained that the famous rock from Syene, in Upper Egypt (so much employed in ancient
