SERPENTINE- 
85 
other rocks; it passes into steatite, but very rarely, if ever, 
into other rocks. The evidence of its igneous origin is less 
than that of primary limestone. I have never seen it in narrow 
veins and dykes like greenstone, neither does it occur resting 
upon other rocks. It rather appears to have been protruded 
between other rocks, as at Middlefield, where on one side it is 
bounded by hornblende, and on the other by mica slate. Chro¬ 
mite of iron, with many varieties of chalcedony and jasper, are 
among its associates. All the localities which I have named, 
furnish it. The serpentine of Troy, Vt., near the Provincial 
line, is traversed by a wedge-form vein of magnetic iron. Like 
primary limestone, it is an unsafe rock for mining. 
Serpentine, when largely mixed with limestone, does not con¬ 
tain chromite of iron. It appears to be absent in the calcareo- 
serpentines of Canada, the St. Lawrence and Champlain dis¬ 
tricts, and I believe also in Sussex, N. J., and Orange county, 
N. Y. Mica and talc, however, in crystals, are common. Large 
plates of bronze-colored mica occur in the serpentine of 
Gouverneur, N. Y., and hexahedral tables of a deep green talc 
at Troy, Vt., associated with arragonite, and octahedral iron 
with brilliant faces. 
The occurrence of so large a quantity of silicious minerals 
not unlike silicious sinter, furnishes some evidence that beds 
of serpentine may have been connected with ancient hot springs. 
Macon county, N. C., especially furnishes immense quantities of 
sinter-like deposit, in connection with serpentine. 
Serpentine is one of the constant associates of this kind of 
limestone, in New York, Canada West, and New Jersey. It is 
frequently disseminated through it in small grains, but some¬ 
times in large masses of an irregular form and rough surface, 
and again in fibrous masses. The grains and masses stand out 
in relief, the limestone weathering more rapidly than the ser¬ 
pentine. This mixed or compound rock, takes a very good 
polish, and might be used for a variety of purposes when the 
rock is sound. The serpentine is arranged in the form of coarse 
