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MINERAL RESOURCES, 1914----PART II.
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1-1/2
feet wide and 1-1/2 feet high. Some of them have yielded tourmaline
gems of fine quality and specimen minerals of interest. The gem-bearing
pockets were found near the middle and in the south half of the east
quarry. Work has been abandoned in this part temporarily, but a good
working face 20 feet high has been made across the north end of the cut
preparatory to removing the spar to that depth southward to the length
of the quarry. Mr. Strickland expects to find more gem pockets when
this block of pegmatite is quarried.
The
tourmalines so far found in the pockets are mostly greenish, showing
many variations as olive-green, yellowish green, nearly grass-green,
bluish green, and pale greenish blue. They range from small size to
large crystals, one of which weighed several pounds. This crystal was
badly broken in quarrying, but some beautiful bluish-green and
greenish-blue gems were cut from the fragments. Another crystal of
transparent green now in the museum of Wesleyan University at
Middletown, Conn., is about 7 inches long. Cut gems are of fine
quality, show good colors, and are brilliant in the paler varieties.
There is little choice between these and the finer gems from Mount Mica
and Mount Apatite, Oxford County, Maine. Mr. Berry states that a few
pinkish tourmalines have been found along with the green, the pink
generally capping a greenish crystal.
Among
other minerals adjoining and lining the walls of the pockets are coarse
flat albite or clevelandite crystals, granular lepidolite, rough quartz
crystals, greenish muscovite crystals, and a little beryl. Much of the
beryl is opaque and yellowish green, but in one pocket an irregularly
shaped fragment of transparent pale salmon-pink beryl was found. It is
2-1/2 inches long and 1 inch thick, with an exceedingly rough
honeycombed and drusy surface. It is evidently the remnant of a much
larger crystal, the greater part of which has been dissolved, leaving
only a part with a rough etched surface. Parts of this would cut into
small gems. In some of the pockets there are mossy tufts or coatings of
minute short hairlike tourmaline crystals of dull greenish-gray color.
Some of these coatings cover a couple of square inches of the surface
of albite crystals and make exceedingly delicate pretty specimens.
Among
other minerals found in the quarry are yellowish-green muscovite mica,
biotite mica, columbite, and a few garnets. The muscovite occurs in
plates up to 12 inches across, but does not have good cleavage. Most of
it is injured by "A" lines and tangle sheet structure so as to be
suitable only as scrap for grinding.
The Riverside quarry is about 2-1/2 miles
east of Middletown on the south side of Connecticut River. It consists
of an open cut 30 to 40 feet across made in the steep northwest slope
of the river bank above the public road. The country rock is mica
schist which strikes north with a variable dip approximating about 20°
W. The pegmatite is about 20 feet thick and apparently conformable with
the inclosing schist. It contains potash feldspar crystals over 2 feet
across, and some albite feldspar, small segregations of gray and smoky
quartz, rum-colored mica in crystals up to 2\ inches across, biotite, numerous beryl crystals, garnets, black and colored tourmalines, lepidolite, and. as reported by Bastin,1 pink to deep salmon-colored fluorite. The
' Feldspar deposits of the United States: U. S. Geol. Survey Bull. 420, p. 50,1910.
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