Perhaps no other gemstone has been as loved and as feared over the centuries as opal. Opal of ancient times, known as Hungarian opal, came from Marmaros in the Nagy-Banya district of what is now Czechoslovakia. The colors scintillate on a white or pale-tinted background, and so this variety, which is also found in Australia, Honduras, and many other countries of the world, is called white opal.
In startling contrast to white opal is the black opal of Australia and Nevada. Against a curtain of dark blue, gray, or black, the opal colors flash in incomparable richness, glowing like a "smothered mass of hidden fire." The black opal from Nevada and Australia is found replacing fossil wood, shells of sea animals, and the bones of extinct reptiles which lived in the days when dinosaurs ruled the earth. Most opal occurs in thin seams in the rock.
The ancient Arabs believed that opals fell from the heavens in flashes of lightning, acquiring their marvelous colors in the process. The ancient Greeks felt that the opal gave foresight and the gift of prophesy to the wearer.
To the Romans, opal was the symbol of hope and purity. In fact, Pliny, the ancient Roman scholar in about 70 A.D., wrote that opal had the fire of the ruby (or the carbuncle), the brilliant purple of the amethyst, and the sea green of the emerald all shining together in incredible union. Opal was thought to prevent disease and to strengthen one's sight. Opal also provided the spirit of truth and the perfection of beauty. It is reported that the Roman Senator Nonius chose exile rather than surrender a large opal to Marc Antony.
Until three or four centuries ago this stone was thought to combine all the virtues of the various colored stones whose hues are united in its sparkling light; however, during the Black Plague in the 14th century opal took on an evil connotation, as it was thought to lose its luster when its owner died of the plague. Opal is thought to be a good thieves stone in that it makes one invisible. It is also thought to preserve blond hair. The birthstone for October is opal.
The fear of damaging an opal is not entirely fair to the species since no gemstone is indestructible. Opal is a bit softer and more fragile than most gemstones, but with proper setting and ongoing care, an opal can last a lifetime. Here are some tips. Generally, the thicker the opal, the better. Look for settings that protect the opal, such as bezel settings where the metal holds the stone all the way around its edges. Prong settings should be avoided.
Because opals contain water, they are prone to drying out which causes them to craze. Avoid storing opals in a bank safe deposit box. The atmosphere in bank vaults is purposely kept dry in order to protect papers. Unfortunately, this climate hastens the drying (and destruction) of precious opal.
When purchasing opal, it is best to buy from a reliable dealer and look for material that is at least one year old since, if the material was prone to crazing, it probably would have occurred by then. When working opal, keep the stone wet and cool to prevent it from shattering.
Copyright © 1995 by Fallbrook Gem and Mineral Society, Inc.
The preceding article was originally published in the May 1995 issue of Lithosphere, the official bulletin of the Fallbrook [California] Gem and Mineral Society, Inc; Richard Busch (Editor).
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Last updated: 18 September 2002