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PRECIOUS STONES
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CHAPTER XIV.
various precious stones—continued.
The Chrysoberyl.
There are
certain stones and other minerals which, owing to their possession of
numerous microscopically fine cavities, of a globular or tubular shape,
have the appearance of " rays" or " stars," and tliese are called "
asteriated." Several of such stones have been discussed already in the
last chapter, and in addition to these star-like rays, some of the
stones have, running through their substance, one or more streaks,
perhaps of asbestos or calcite, some being perfectly clear, whilst
others are opalescent. When these streaks pass across the star-like
radiations they give the stone the appearance of an eye, the rays
forming the iris, the clear, opalescent, or black streak closely
resembling the slit in a cat's eye, and when these stones are cut en cabochon, that
is, dome-shaped (see Chapter XI. on " Cutting"), there is nothing to
deflect the light beams back and forth from facet to facet, as in a
diamond, so that the light, acting directly on tliese radiations or
masses of globular cavities and on the streak, causes the former to
glow like living fire, and the streak appeal's to vibrate, palpitate,
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