specimen
is an inch and a half thick, showing two surfaces which have evidently
come from the walls of a vein. The color and association of the beryls
are similar to those on Mount Antero, Colo., but so far the California
locality has not yielded crystals of gem quality.
CONNECTICUT.
The
beryl locality near Merryall, Litchfield County, Conn., has been
mentioned by George F. Kunz in these reports for the years 1885, 1892,
1898, and 1899. The beryls were obtained as an important by-product
from a quarry worked for feldspar and mica. The deposit has been idle
since about 1900, and the workings are now in an overgrown condition.
Formerly the mine was owned by two parties, S. L. Wilson and George
Roebling, but the whole property is now held by Mr. Roebling, of
Northville, Conn. An examination of the deposit was made in October,
1914, at which time the following notes were taken:
The deposit is located 5| miles N. 12° W. of New Milford, or 3 miles east of Kent, a station on the New York, New Haven & Hartford
Railroad. The workings consist of an open cut about 120 yards long
driven southwest into a hillside. The cut varies from 10 to 50 feet
deep in the deepest part and is 30 to 40 feet wide in the northeast
half. The northwest wall overhangs the workings, and the southeast wall
dips northwest at varying angles. A little tunnel work has been carried
on along the hanging wall. The open cut was originally 65 feet deep
toward the northeast end, but this part has been partly filled up by
the caving of wall rock. The country rock is biotite gneiss, highly
schistose near the vein and has been mapped as Becket gneiss by Rice
and Gregory.1 Immediately around the mine the gneiss has a
due northeast strike with a vertical to high northwest dip. The vein
rock is pegmatite, which varies from 20 to 40 feet thick. It strikes
about parallel with the country rock, but cuts across the schistosity
of the latter with a lower dip to the northwest. The
E
egmatite pinches and
swells in different parts and is reported to ave been thinner near the
bottom of the cut than at the surface. The texture of the pegmatite is
extremely coarse grained. Gray quartz occurs in large massive streaks
several feet in thickness, lying roughly parallel with the walls of the
pegmatite, orthoclase feldspar in crystals and masses several feet
across, and mica in bunches and pockets in various parts of the vein.
The best mica and feldspar is reported to have come from the northeast
half of the open cut and the best beryl from the southwest half. Near
the southwest end of the cut there are outcrops of quartz streaks 2 to
3 feet thick and masses of solid mica of even greater thickness, and
one 50 feet long. This solid mica is composed of rough "A" and
"wedge-shaped" crystals, 1 to 4 inches across, bunched closely
together, with a little impurity such as quartz and feldspar mixed with
it. One block of solid mica blasted loose from this vein measured 4
feet thick and 8 feet long. Such mica would only be valuable as scrap
for grinding, but it is probable there are at least 50 tons in sight.
The mica from the northeast end of the cut was suitable for glazing,
yielding clear sheets several inches across. Large quantities of
1
Rice, W. N., and Gregory, H. E., Manual of the geology of Connecticut:
Connecticut State Geol. and Nat. Hist. Survey Bull. 6,1906.
