Opal has been mined
through history in India, Mexico, what is now Czechoslovakia and possibly even
in central Africa. People of the Far East prized opal as a symbol of purity and
considered that the wearer of the gem was protected from illness. To the
Romans, opal was a much valued stone as well, being considered not only a
universal good luck charm, it was also used as a preventative medicine towards
any eye disease, it was thought to have aphrodisiacal qualities, not to mention
having the capacity to bring great wealth to it’s owner. Therefore, history in
general has considered opal a very good gem to have around. It has even been
found in some Aztec tombs.
What caused the “bad
luck” tag to develop in some areas of the world? Popular belief is that the
diamond merchants of the mid 19th and early 20th century
saw the beauty and color of the opals and feared that it was going to be a
serious threat to their livelihood. Since 95% of gem quality opal was now being
mined in Australia and very commercially available they feared that it would
eclipse the diamond. Therefore they went about spinning a tale of “bad luck”
around the stone in hopes of limiting its popular appeal.
In this present age of
enlightenment, however the bad luck tag is now disbelieved by most. It is
easier to consider the many real life stories about opal, where ordinary men and
women in the opal fields have become wealthy by this magnificent gemstone.
What is an
Opal?
Opal was formed millions
of years ago, when silica and water, mixed together, flowed into cracks and
spaces in the ground, formed a hydrous gel (or silica that has retained a small
water content) then gradually solidified and became opal. Most of Australia’s
opal fields were formed about 100 million years ago. Opals hardness is between
5 ½ and 6 ½ on the Moh’s hardness scale. It naturally has a water content,
which varies quite considerably, but is usually between three and ten percent.
It is this presence of water that causes an opal to have the wonderful “play of
color” which makes opal so fascinating. The colors are generated as light
travels through the water in the stone and is refracted into its spectral
colors. Milk opal is mostly white and is inexpensive. Opals with red and blue
colors will be some of the most prized. Black is the most valuable base color
for opals and therefore carries a premium price. In order for a stone to be
truly black, it must have a rich dark black background. But because nature is
not so well organized, base colors come in all shads of gray. Additional
varieties include Fire opal which is semi transparent and orange in body color;
Jelly opal which is a solid transparent opal with no play of color; crystal opal
which is also transparent, showing a play of color but no base color and semi
black opal which is translucent to opaque when viewed from the top and which has
a play of color against a dark background. With such an overwhelming selection
of “opal” there is something for everyone to love about this truly unique
gemstone. Those born in October are “lucky” to have it as their birthstone…but
now that we know that through history there is no bad luck to owning an opal, we
can all treat ourselves!!!
