Sugar Hill.—Two fine aquamarines, found near Sugar Hill, in the western part of Stoneham, are described as follows by Kunz: a
The
writer obtained at Stoneham, Oxford County, Me., two beryls,
exceptional for the United States. These were found in 1881, several
miles apart and several miles from the topaz region, by farmers who
were traversing pastures in the township. The first was found in two
pieces, as if it had been roughly used, and broken, and discarded as
worthless, or else broken in taking from the rock and then rejected,
its value not being known. This crystal measured 4= inches (120
millimeters) long and 2-1/10, inches (5-1 millimeters) wide, and was
originally about 5 inches (130 millimeters) long and 3 inches (75
millimeters) wide. The color was rich sea green viewed in the direction
of the longer axis of the prism, and sea blue of a very deep tint
through the side of the crystal. In color and material this is the
finest specimen that has been found at any North American locality, and
the crystals, unbroken, would equal the finest foreign crystals known.
It furnished the finest aquamarine ever found in the United States,
measuring 1-2/3 inches (35 millimeters) by 1-2/5 inches (35
millimeters) by three-fourths inch (20 millimeters). It was cut as a
brilliant and weighs 133-3/4 carats. The color is bluish green, and,
with the exception of a few hair-like internal striations, is perfect.
In addition to this remarkable gem, the same crystal furnished over 300
carats of fine stones.
The
other crystal is doubly terminated, being 1-3/5 inches (41 millimeters)
long and 3/5 inch (15 millimeters) in diameter. Half of it is
transparent, with- a faint green color; the remainder is of a milky
green and only translucent.
The
large 133-carat gem cut from the first of these two crystals is now in
the possession of the Field Museum of Natural History at Chicago.
Fine crystals of golden beryl have been obtained at Edgecomb Mountain in Stoneham.
On
the south flank of Sugar Hill a ledge of coarse pegmatite has yielded a
number of fine transparent beryls. The pegmatite mass here appears to
be rather flat lying and, as exposed in a near-by vertical face, is at
least 15 feet in thickness; it can be followed for 100 feet or so along
the hillside. The buff-colored potash feldspar of this ledge forms
large enough crystals and is sufficiently free from iron-bearing
minerals to be of commercial grade for pottery purposes, but its
distance from the railroad would render its exploitation unprofitable
at the present time.
Crystals
of beryllonite, a phosphate of beryllium and sodium, have been found in
western Stoneham on the farm of Eldin McAllister, on the south side of
Sugar Hill, a few rods below the beryl locality just described. When
visited by the writer, in September, 1906, the only opening consisted
of a small pit dug in the talus and glacial drift near the foot of the
hill. The soil in which the beryllonite crystals were found contains
also fragments of quartz, feldspar, and mica, and a few of apatite,
beryl, cassiterite, columbite, and triplite. Some of the beryllonite
crystals themselves are attached to apatite and some retain what appear
to be the impressions of muscovite crystals. There can be little doubt therefore that the beryllonite occurred
a Kunz, G. F., Gems and precious stones, pp. 92-93.
