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Adularia moonstone
A microperthitic association of orthoclase and
albite (with r predominance of orthoclase). Because of its
slightly turbr: transparency, gems cut en cabochon show a
mobile reflection, which is softer and more diffuse than that
of chatoyant stones.
Appearance Moonstone generally has an almost
transparent ground, which is practically colorless, pale gray,
w tinged with yellow, with a whitish to silvery white or bfuc
shimmer. It is normally cut into cabochons or curvec: pieces
for threading into necklaces, etc. Incipient cleavage cracks
may be visible inside the stone.
Distinctive features Adularescence (a slight
turbidits with a mobile reflection) is in itself distinctive.
Another feldspar, albite, can look identical (for the same
reason) and ia also called moonstone. If necessary, the two
may be distinguished by their density, which is lower in orthoclase.
An imitation form consisting of synthetic spinet is much milkier
in appearance, without a mobile reflection.
- Occurrence Adularia
moonstone is found mainly in Sri Lanka, Burma, India,
Australia, Madagascar, Tanzania, the United States, and
Brazil.
- Value Fairly
low, but the type with a blue reflection is quite highly
prized.
- Simulants and synthetics
It has been imitated by milky synthetic spinet,
which does not have a proper mobile reflection. It has
not been manufactured synthetically.
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