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opal also contains fire, but the body color is dark
gray or black This accentuates the color play, producing
a dramatic effect. Black opals are extremely rare and
costly.
Water opal is transparent, colorless opal that contains
brilliant flashes cu color swimming within it.
Fire
opal is transparent or translucent opal with an orange
or red body color. It may or may not display fire. The
term "fire opal" is frequently misused.
Opal
that has a color play is called precious opal. The color
play itself is called fire. Fire opals are simply reddish
or orange opals usually turbid, that may not have any
fire!
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The
ancient Romans had a passion for fine opals, and the
Senator Nonius had one coveted by Marc Antony. Nonius
was forced to choose either giving up the gem or exile
from Rome; he chose the latter. This esteem of opal
continued until the 17th Century, but afterward lost
popularity. Part of this is connected with the superstition
of opal as a "hard luck" stone. |
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This
attitude may have been caused in part by a novel by Sir Walter
Scott called "Anne of Geierstein," in which an opal
played a malevolent role. Sales of opals dropped drastically
after publi¬cation of this book, and did not fully revive
until the present time. A 70 major part of the "bad luck"
reputation is probably due to the tendency Of opal to track
spontaneously.
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| OPAL
Opal has been called the Queen of Gems. Few descriptions
are adequate to describe the finest opals: a white,
snowy landscape dotted wit fireflies of red, gold,
blue, purple, and green; a black night streaked
with rainbow lightning; the aurora borealis captured
in stone. Mysterious, ¬elusive, varied, and
delicate, opal has been treasured since ancient
times for its unique properties and beauty.
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Opal
is silicon oxide, and thus closely related to
chalcedony. But while chalcedony is just silica,
opal contains a variable amount of water in its
structure. Opal is softer than quartz gems, about
5 1/2 to 6 1/2 on the Mohs scale, and is much
more fragile and brittle than chalcedony. But
what makes opal distinctive is its unique play
of color, called "fire. |
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Most
opal is dull and lifeless, and so-called "common opal"
tends to be gray or yellowish, occasionally waxy looking and
translucent. Once in a great while a piece is found transparent
enough to facet. Otherwise common opal has little or no gem
value. Unlike quartz, which forms good crystals, opal is more
like a hardened jelly, or "gel."
There are four types of gem opal:White opal is opaque, white
material that looks much like porcelain The colors appear
as flashes, speckles, or sheets of rainbow color, White opals
are the kind most commonly seen in opal jewelry. |
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