468 
GEOLOGY OF THE FIRST DISTRICT. 
colors, black spinelle in hemitropes, magnetic oxide of iron in large rough octohedral crystals, 
hornblende, and blackish serpentine.* 
A locality two and a half miles north of Edenville, affords beautiful groups of crystals of 
spinelle. The rock in some parts might be called Spinelle rock, but contains some carbonate 
of lime, which, when dissolved out by an acid, brings to view the brilliant large groups of 
crystals of spinelle. An aggregate of hornblende, mica and limestone, also forms masses of 
rock in this hill. Crystals of zircon, pargasite, black hornblende, and yellow brucite, also 
occur here. 
At a locality between Mounts Adam and Eve, red and black spinelle, red brucite, augite, 
green hornblende, idocrase and scapolite are found. 
At the southern base of Mount Eve, at an old mine hole, where a deep excavation was 
once made in search of the precious metals in the white limestone, beautiful crystals of green 
and brown hornblende are found in the limestone and scapolite. Crystals of zircon are also 
found in the scapolite. Augite, brucite and spinelle also occur there. 
Another locality south of the above, is three-quarters of a mile north of Edenville, It 
affords fine crystals of the hair-brown hornblende called edenite. The crystals are terminated, 
and imbedded in an aggregate of white limestone and brown mica. The edenite also occurs 
in loose boulders of limestone a little farther north. Brucite of various colors, pargasite and 
reddish brown mica occur in the same blocks. 
About forty rods north-northeast of the last locality, is a vein of arsenical iron in limestone. 
The limestone contains massive hornblende and augite. Scapolite, augite and sphene also 
occur in the immediate vicinity. Arseniate of iron coats the surfaces in the fissures of the 
ore. 
The above localities, and an abstract of the remarks on them by Prof. Shepard, is from 
the American Journal of Science, Vol. 21, pp. 324, 332 ; and I have added some observations 
of my own, from memory of the localities. I have visited them all, and a great number of 
others, where the phenomena connected with geology were better calculated to interest the 
geologist, and where there was also much to interest the mineralogist; but my notes are lost. 
The following remarks, however, by Prof. H. D. Rodgers, on these rocks, their meta- 
morphic changes, and their associated minerals, will supply the same kind of evidence that 
I have received from personal observation. 
“ Following the range of the crystalline limestone somewhat more in detail, we shall com¬ 
mence our description of its geological features where it first conspicuously shows itself, in 
the neighborhood of Amity, in New-York. Here, and for several miles to the southwest, 
the belts of altered rock occupy a very considerable width, in the valley ranging from Mounts 
Adam and Eve towards Hamburgh, forming a zone averaging at first half a mile in breadth, 
but contracting to two or three hundred yards. The crystalline material in its most perfect 
form does not, however, fill the whole space, but occupies rather a series of closely adjacent 
parallel bands, most numerous towards the middle and northwestern side of the valley, where 
Shepard, American Journal of Science, Vol. 21, pp. 230, 231. 
