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MINERAL RESOURCES, 1913----PART II.
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The
Beryl Hill gems range in color from light to dark aquamarine, fine
blue, yellowish green, to golden. Many very fine bluish-green stones
have been cut, and among those seen was a table-cut stone of 13f
carats. The blue beryls of better quality are rarely excelled by those
from other localities in brilliance or beauty of color. Among cut gems
of this quality a 12-1/2 carat brilliant cut stone was especially
beautiful.
NEW HAMPSHIRE.
A deposit has been worked for gem beryl on Melvin Hill, 2-1/4 miles
S. 25° W. of Grafton, N. H., by F. H. C. Reynolds, of Boston. Two
openings were made about 150 feet apart at the east side of the hill
and about 400 feet higher than the valley below. The principal working
is a quarry with a working face over 80 feet longin a X. 60° W.
direction along the hillside and 5 to 15 feet high. The country rock is
quartz-biotite gneiss which strikes north with a nearly vertical dip
and some folding. The pegmatite cuts across the foliation of the gneiss
with a north of west strike and a dip of about 20° X. The contact with
the gneiss is not regular but rolling, with a few smaller beds of
pegmatite extending out into and parallel with the foliation of the
gneiss. The bottom of the pegmatite is not exposed in the workings.
The
pegmatite is composed of the usual minerals, potash feldspar, quartz,
and mica, with other associated minerals. The feldspar occurs in large
pure crystal masses or graphically intergrown with quartz. The quartz
is mixed through the pegmatite in grains and massive irregular
segregations. It is either white or smoky and some of it is quite
translucent. Muscovite mica of good quality occurs rather abundantly
and would pay part of the mining cost if saved. Much biotite mica was
observed on the dumps, and in many specimens biotite was intergrown
with muscovite. Among other minerals in the pegmatite are black
tourmaline, red garnets, green apatite, and beryl. Beryl was evidently
rather plentiful for there were many fragments of broken crystals on
the dumps. Some of the crystals measured several inches across, and
most of them were opaque or only translucent. In some of the crystals
Mr. Reynolds reports clear gem beryl was found, the golden variety of
which was especially finely colored. Light golden beryl gems weighing
several carats were cut from some of the crystals, but the dark golden
beryl crystals yielded only gems of less than 1 carat weight. The
colore observed in the beryl fragments on the dumps were light yellow
to rich golden yellow, yellowish-green, and light to dark aquamarine
green and greenish-blue.
The
other opening of the Reynolds Beryl mine is south of the main working.
A pit was made in pegmatite cutting biotite granite and quartz-biotite
gneiss. The pit and dump were overgrown with brush and little could be
seen.
Another
beryl deposit was worked about one-third of a mile west of the Reynolds
mine, near the summit of Melvin Hill, by the Columbian Gem Mining Co.
The gem beryl found was mostly the aquamarine variety. Another beryl
prospect has been worked about 2 miles west of the Reynolds mine and
about 1 mile south of Prescott Hill, by Franklin Playter, of Boston.
None of these mines was in operation during 1913.
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