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Green Grossular
The green variety of grossular garnet, discovered
a fFdecades ago and found mainly in Kenya, near the Tsa. National
Park, is also known as Tsavorite (or Tsavolite)
Appearance It is a light, verdant,
or dark green, simii to the color of the better green tourmalines
and sometime it is said, even comparable to African emerald.
It has goc luster. These gems, which are usually given a round
pear-shaped mixed cut, or occasionally a brilliant cut, a
generally small, rarely exceeding one carat and nev more than
a few carats.
Distinctive features Being singly refractive,
green grcsular is distinguished from green tourmaline, by
the latter strong birefringence and pleochroism, and from
mar green zircons, which are obviously birefringent, wherer
measurement of the physical properties is necessary distinguish
it from green sapphire when the latter does n display clear
pleochroism. It is very similar in all respects a recent artificial
product of comparable structure, nams green YAG (Yttrium Aluminium
Garnet), from which it distinguished by its physical properties.
Occurrence It is very rare; being found mainly
in Ken. and Tanzania, but also in Pakistan.
Value If a good color (a lively, strong green),
it can be the top price bracket for secondary gems; this is
especial true of the very rare examples weighing a few carats.
Little known by the general public, it is in demand by collectc,
and connoisseurs.
Simulants and synthetics Green grossular
has or . been known for a few decades. Green YAG (an artific
- product with the structure of garnet, but not containing
s con) closely resembles it and can be a good imitation. It
not produced synthetically.
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