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Synthetic Emerald
The (emerald) green variety is the only one
which is manufactured synthetically on an industrial scale.
Production has been attempted by a number of companies, some
of which have subsequently abandoned the task as uneconomical.
Appearance It is usually quite a strong emerald
green, with a bluish tinge, and, as with natural emeralds,
the step or trap cut is normally used, mixed oval or pear-shaped
cuts being rarer. Cut stones are generally quite limpid, although
stones of this quality take longer to grow. All in all, their
outward appearance is very similar, it not identical, to that
of their natural counterparts.
Distinctive features It was mentioned in
the discussion on physical properties that accurate measurement
could reveal differences between the refractive indices, birefringence,
and density of natural emeralds and the synthetic ones produced
by the flux melt process. The stones are normally distinguished,
however, by their inclusions.
In the case of hydrothermal synthetic emeralds,
these are not very different from some inclusions in natural
emeralds, but they are "oddly" arranged in relation
to the growth lines and are also positioned like mirror images
of one another on either side of a thin central plate constituting
the seed onto which the synthetic product was grown. Emeralds
produced by the flux melt process contain variable quantities
of swirling, veillike inclusions consisting of whitish residues
of flux material trapped in cracks that developed during their
formation. But it is admittedly not easy to distinguish between
synthetic and natural emeralds without a good microscope,
a lens alone often proving inadequate.
Cost The cost of stones with
few inclusions is quite high, equal to certain prized secondary
gems, but much lower than that of natural emeralds. Stones
with copious inclusions are worth somewhat less, but are still
among the highest-priced synthetic stones.
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