their
color, or become entirely filled with fissures, more especially the
very limpid varieties with the flames of color. Often the stones, with
only a small loss of color, have become entirely flawed, the cracks
being such as to render the stones unfit for setting, since they are
liable to break.
Dr. Augustus C. Hamlin1
gives the two following illustrations of the loss of fire in opals: "A
traveller from Central America brought home a splendid rough fire-opal
which dazzled the eye with its fiery reflections. It was taken to an
honest lapidary, who received it with a doubtful look. The next day the
opal was returned, having been shaped into the usual oval form, but
only faint gleams of any of the colored rays flashed from its surface
or the interior. ' Is this the gem which was given you
yesterday ?' was demanded of the artisan. With a smile the lapidary
took the transparent stone, and roughened its finely polished surface
upon the wooden wheel. In an instant the lost fire returned, as if
directed by magic's wand. The perfect transparency of the gem, with its
high polish, had allowed the rays to pass directly through it, and
there was but little refraction, but on roughening the surface the
light was interrupted, and the peculiar property of the mineral
displayed. Unfortunately the lesson was not concluded here. At the
last touch of the wheel the beautiful gem flew into two parts, and its
glories departed in an instant. Saddened with the day's experience, the
two fragments were taken, cemented together, and tossed into a drawer
which contained other mineral specimens of no great value. Some months
after, when searching for a misplaced mineral, a gleam of light
suddenly flashed out as the drawer was again opened. It was the
neglected and abused opal, which now gleamed with the energy of a
living coal of fire. It had recovered its beautiful reflections, and
still adorns, notwithstanding its fracture, a most cherished jewel.
Whence this mysterious change? the reader may ask. It can only be said
that the complete transparency of the stone had been lessened, and
perhaps the change was due to the action of some of the ingredients of
the cement with which the fragments of the broken gem were united."
1 Leisure Hours Among the Gems, 8vo., Boston, 1884.