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Glittering
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Glittering Stones Glossary o
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- Opal
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Most opal is 50-65 million years' old,
dating reverse to the time of dinosaurs in the Cretaceous
period. Opal created as silica from decomposing rocks that
assorted with ground water and formed a silica gel which hardened
in underground cavities and fissures.
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- Opaque
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In gemstone use, an opaque
gem is one which does not allow light to pass through it,
is not transparent or translucent.
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- Onyx
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A variety of chalcedony quartz,
frequently with parallel banding. When chalcedony is variegated
it is called agate. Black onyx might be opaque
or translucent and though it does occur obviously in black,
it is usually dyed to darken its color.
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