EMERALDS
E
MERALD is now but a
general trade designation for various green precious and semi-precious
stones and not, in the jewelry trade, the specific term of any gem
mineral. Beryl, of the accepted green emerald hue, is the true or
standard emerald. In the view of the mineralogical experts of the
United States National Museum, recognition is accorded to five other
varieties of " emeralds "; they are: Brazilian-tourmaline,
Congo-dioptase, Evening-olivine, Oriental-corundum, and
Uralian-gar-net. The green beryl, excepting in its colour, is the same
mineral as aquamarine, golden, and other variously coloured beryls. One
of the rarest of gems is a flawless emerald-hued beryl.
The
crystallisation of the beryl is in the hexagonal system, usually long,
and often having the prism faces more or less deeply striated
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