Throughout history, the opal has been considered to be lucky (the Ancient Greeks and Romans) and unlucky (Medieval Europe). Some say it is only lucky for those born within the month of October (lucky me!). Descriptions of opal are never mundane. Words such as pure, evil, precious, love and hope are used to describe this incredible gem.
My description of the opal - Mysteriously Beautiful!
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| Massive Blue Banded Opal from the Barco River, Queensland, Australia. Photograph taken at the National History Museum, London, England. Photo released to Public Domain by author (Wikimedia Commons) |
I love rocks and am known to go out of my way to visit rock shops! I can spend hours in the study of how rocks are formed and in particular colored stones. Everything from quartz to diamonds! I find semi precious to precious gems to be beautiful reminders of just how incredible this world can be. It's a fascinating study, searching the origins of colored stones and realizing how each one has its own particular makeup. One sparkler that really gets my attention is the opal. Seeing a raw Australian boulder veined with flashing color is something special indeed. Understanding that this was actually a process of rain seeping into crevices and then the silica bearing waters drying into beautiful bands of striking color always confirms the mystery of nature. How does play of color occur? Read on to find out.
I grew up with thinking of the opal as special to Australia. A majority of precious opal does comes from Australia. Mining areas such as Coober Pedy and Lightning Ridge used to conjure up images of mystery and adventure in my mind.
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| Multi-colored rough opal specimen from Virgin Valley, Nevada, US Photo released to Public Domain by author (Wikimedia Commons) |
Opal appears in most parts of the world as common opal, with particular
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| Beautiful play of color in this Ethiopian opal. |
Common opal or what miners call 'potch' is opal that does not show any play of color. Common opal has a milky or pearly opalescence appearance. It comes in many different colors, such as black, white, colorless transparent, blue and purple.
Basic information to be considered when purchasing an opal:
- Color - Play of color and background color. Play of color is microscopic spheres of silica which are arranged in an orderly manner. As light passes through the spheres it is diffracted, showing the colors of the spectrum. The colors are determined by the size of the spheres and the geometric makeup.
When turned in the light, opals with play of color are incredibly beautiful.
- Pattern of play of color. There are many different patterns, such as pinfire, peacock's tail, palette, flagstone and exploding flash to name just a few.
- Clarity - Transparency and whether there are inclusions or not. Inclusions in opals can be just as important to the functionality of the gem as well as the beauty of it, as opals with inclusions can fracture easily.
Wood as well as shells can be opalized.
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| Petrified Wood with Common Opal - Photo released to Public Domain by author (Pixabay) |
There are several types of opal, such as black, white, jelly, boulder, crystal and fire. They all have different types of beauty and qualities. Black opal is usually considered the most valuable, depending on the quality of the stone.
Opal is about 5.5 to 6.0 on the Mohs scale of hardness. That means that while it is a beautiful stone for the use of jewelry, consideration needs to be made on what type of setting is used. Much to my personal dismay, opal cracks rather easily. I found out about that aspect of my favorite stone the hard way by having a beautiful ring crack. Best not to use a prong setting for a ring. There isn't enough protection. A bezel setting is much better. Opal is best used in earrings, brooches and necklaces where they have less of a chance to receive rough contact with other surfaces. Opals can also crack or splinter due to dryness. They need moisture and do not do well stored in sunlight or heat. Most opals are cut and polished in the form of a cabochon.
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| Mexican Fire Opal - Intense, brilliant colors! Fire Opals may have some play of color, but the term refers more to the intense colors of the opal, usually reds, oranges and yellows. Photo released to Public Domain by author (Wikimedia Commons)
Ancient Romans gave opal its name,
'opalus' which means 'Precious Stone'.
The opal symbolized 'love and hope'
in the Roman society.
(info provided by Gia.edu) |
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| Australian Precious Opals with Matrix Photo by Laurie A |
Sources:
Opalsdownunder.com
Australian Precious Opal by Archie Kalokerinos
Gia.edu
