vein imparted to it a new and more significant character. The mica,
called by Mr. Atwood, the superintendent of the work, "book mica,"
occurs in thick crystals, ranged heterogeneously together in stringers
and "chimneys," and brilliantly reflecting the sunlight from their
diversely commingled laminae. This mica yields stove sheets of about
two to three by four or five inches, and is of an excellent,
transparent quality. It seems to be a true muscovite, and is seldom
marred by magnetic markings or crystalline inclusions that would
interfere with its industrial use. Seams of decomposition occur, and a
yellowish scaly product, composed of hydrated mica flakes, fills them.
The mica does not everywhere present this coarsely crystalline
appearance, but in flexures and lines of union with the quartz and
orthoclase is degraded to a mica schist upon whose surfaces appear
uranates of lime and copper (autunite and torbernite), and in which
are inclosed garnet crystals of considerable size and beauty. The
enormous masses of clean feldspar made partially "graphic" by quartz
inclosures are a conspicuous feature of the mine. In one part of the
mine, wooden props support an overhanging ledge almost entirely
composed of feldspar, which underneath passes into the gray brecciated
quartz, which again grades into a white, more compact quartz rock. It
is in this gray brecciated quartz that the beryls are found. These
beautiful stones vary extremely in quality and color. Many of the
large crystals are opaque, extensively fractured, and irregular in
grain, but are found to inclose, especially at their centers, cores of
gem-making material.

The colors of the beryls grade from an almost colorless mineral
(goshenite) though faintly green, with blue reflections, yellowish
green of a peculiar oily liquidity (davidsonite), to honey yellows
which form the so-called "golden beryls" of the trade, and which have
a considerable value. These stones have a hardness of 8, and when cut
display much brilliancy. Many assume the true aquamarine tints, and
others seem to be almost identical with the "Diamond of the Rhine,"
which as early as the end of the fifteenth century was used as a
"fraudulent substitute for the true diamond" (King). Few, very few,
belong to the blue grades, and the best of these cannot compare with
those from Royalston, Mass. Those of amber and honey shades are
beautiful objects, and under artificial light have a fascination far
exceedi