No. 275.] 137 
Monroe works, about three miles from the latter place; also to many 
places on the turnpike from the saw works to Bellvale, in Warwick. 
Immense quantities of rock are found every where in the Highlands 
of Orange, which are neither perfect granite or gneiss, but partake of 
the character of both, or is intermediate between the two; and it is this 
granitic gneiss or gneissoid granite, which embraces a large number of 
the metalliferous deposits found in the county. 
HORNBLENDE ROCK. 
Extensive strata of this are found in the Highlands, which are well 
characterized. The most extensive one observed forms the middle of 
the southeastern face of the mountain first east of the valley of Long 
pond, in Warwick. This stratum is, perhaps, twenty-five rods wide. 
An extensive stratum also runs through the Forest of Dean, along the 
western margin of the white primitive limestone. Magnetic iron ore 
is associated with this stratum in many places. 
In addition to what has already been remarked of the foregoing 
granitic rocks, it should be further stated that the feldspar is generally 
in a larger proportion than the quartz. The colour of the quartz is 
white and bluish, or reddish white. The mica is black, green or inter- 
mediate shades of these colours, and the feldspar white, yellow, red 
and greenish. The hornblende black, gray or greenish. 
The minerals embraced in the foregoing rocks are numerous and im- 
portant. 
First are the ores of iron; all the magnetic oxides are found in them. 
They also contain adularia, fibrolite, kyanite, manganesian, garnet, ser- 
pentine, mica, plumbago, sphene, red oxide of titanium, crystallized 
hornblende, epidote, tremolite, zircon, crystallized augite, tourmaline, 
coccolite, sahlite. 
Beds of other mineral substances are also embraced in the granitic 
rocks. In the town of Monroe is a bed of quartz. It is two and a 
half miles southeast of Greenwood furnace. Its northeast end only is 
visible. At this place it is four rods wide, and rises fifteen feet above 
the gneiss on each side. It is visible for more than twenty rods, and 
gradually disappears beneath the surface. The quartz is white and 
nearly opake, containing in many places pale green coccolite. 
Augite rocks exist in many localities; the surfaces are often covered 
with fine crystals. This may be seen at Greenwood furnace, Monroe, 
[Assem. No. 275.] 18 
