No. 276.] 
33 
52. Localities of this mineral abound in the county of Madison. It 
is sometimes foliated and granular, but usually, as in the above county, 
it belongs to the common or impure variety. It occurs imbedded in 
gypseous marl, every where forming irregular or somewhat rounded or 
conical masses rarely more than forty or fifty feet in diameter, and usu- 
ally from ten to twenty feet in height. These hillocks seem to be de- 
tached, and the conclusion is almost irresistible that they have been 
formed after the upper strata of rock have been deposited. The masses 
of gypsum are a foot or more in thickness, and weigh from four to six 
hundred tons. I can give no details concerning the amount of this mi- 
neral annually raised in this county, but in the town of Sullivan alone 
it is said to be from four to seven thousand tons. 
On the route from Chittenango to Syracuse, in Onondaga county, 
conical elevations similar to those already noticed are of frequent occur- 
rence; some of which have already been opened and found to contain 
deposits of gypsum, while others are left as the reward of future enter- 
prise and labor. 
53. The interesting region around Onondaga lake, of which I have 
heretofore attempted to give an account, contains, in addition to its 
other sources of wealth, some important deposits of gypsum. At 
Liverpool, the fibrous variety, then comparatively rare in this State, 
was found several years since, about twelve feet below the surface of the 
earth, associated with marly clay. Recently the excavations made for 
the construction of the rail-road from Syracuse to the Split-Rock quarry, 
have opened an extensive bed of the same valuable mineral. At this 
locality are to be found several varieties; as the foliated, the fibrous, the 
snowy, and the common or dark coloured — the whole imbedded in a kind 
of gypseous marl which effervesces freely in acids, and contains variable 
proportions of the oxide of iron. Gypseous beds, similar in their 
general characters, also occur in the vicinity of Manlius, from which 
large quantities have been exported. But probably the most valuable 
deposits that have yet been opened up are those along the line of the 
Syracuse and Auburn rail-road, near the village of Camillus. We find 
here, among other varieties, noble specimens of transparent selenite, 
and what renders the locality peculiarly interesting, are the associated 
strata of calcareous tufa, and of the singular hopper-form crystals of 
marly clay. From forty to fifty thousand tons of gypsum have been 
obtained simply from the excavations which were necessary for the con- 
struction of this road. And this may be considered as merely a speci- 
men of what is still hidden in the adjoining hills. 
[Assem. No. 275.] 5 
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