Opal is given as a symbol of hope, happiness and truth.
Color: Opal is fundamentally colorless, but such material is rarely found. Disseminated impurities generally impart to opal various dull body colors that range from the yellows and reds derived from iron oxides to black from manganese oxides and organic carbon.
The milkiness of many white and gray opals is attributable to an abundance of tiny gas-filled cavities in them. Precious opal reflects light with a play of brilliant colors across the visible spectrum, red being the most valued.
Description: Amorthous silica, SiO2 + nH2O, A solidified jelly so it has no crystal structure and contains up to 13% water. Precious opals are translucent to transparent and are distinguished by a combination of milky to pearly opalescence and an attractive play of many colors. These colors flash and change as a stone is viewed from different directions are caused by interference of light along minute cracks and other internal inhomogeneities.
Opal is extensively used as a gemstone. Various forms of common opal are widely mined for use as abrasives, insulation media, fillers, and ceramic ingredients.
The name's origin: The name opal is derived from the Latin word opalus, meaning seeing jewel. According to another theory the word opal comes from upala, a Sanskrit word simply meaning a stone.
Birthstone: Opal along with tourmaline are birthstones of Libra (Balance): Sept. 23 - Oct. 23.
Wedding anniversary: Opal is the anniversary gemstone for the 14th and 18th years of marriage.
Varieties: Black opal, with a very dark gray or blue to black body color, is particularly rare and highly prized.
White opal has light body colors.
Fire opal is characterized by yellow, orange, or red body color. White and Fire opals are much more common.
Care and treatment: Opals develop crazing if they are exposured to sun and allowed to dry out. In addition to cracking, loss of water causes loss of iridescence, therefore they need to be oiled regulary to keep the water inside. Opal also must be protected from detergents that dry the gem. And always remember, opals can be fairly brittle because they contain water.
From the stone history: The most striking quality of opal is its ability to refract and reflect specific wavelengths of light. The interplay of different wavelengths of light gives opal its unique visual appeal, and makes it one of the most sought-after gemstones in the world at all times.
Precious opal has been a gemstone since Roman times. Opal was included among the noble gems and was ranked second only to emerald by the Romans. A beautiful opal called the orphanus was set in the crown of the Holy Roman Emperor. It was described "as though pure white snow flashed and sparked with the color of bright ruddy wine, and was overcome by this radiance." Opals are also set in the crown jewels of France.
Most opal is more than 60 million years old and generally dates back to the Cretaceous period when dinosaurs roamed the earth. Most of the precious opal marketed in ancient times was obtained from occurrences in what is now Slovakia.
Shopping guide: Fire opals usually are facet cut, but most other precious opals are finished en cabochon because their optical properties are best displayed on smoothly rounded surfaces. Because opal may crack or lose its color if it dries, many finished stones are protected by water or films of oil until they are sold. Light-colored stones are often dyed to resemble rarer, more deeply colored varieties.
There are several opal imitations and even some synthetic opals on the market. As always consult the proffesional before gems shopping. Examine the opal very carefully before you buy it to avoid the purchase of the crazed stone.
Opals range from very inexpensive stones which are the almost pure white milk opals, to the very expensive black opals. The cost of Black Opal may reach US$ 20.000 per 2 gr.
Healing ability: Opal has been described in medival times as a cure for diseases of the eye.
Fire Opal: Red corpuscle & blood disorders; depression; apathy; lethargy;
Black Opal: Reproductive organs; spleen & pancreas; filters red corpuscles & aids white corpuscles; bone marrow; depression, especially of sexual origin;
White Opal: Balances left and right brain hemispheres for neuro disorders; stimulates white corpuscles;
Mystical power: Black opal is regarded as an extremely lucky stone. In ancient times opal was accepted as a symbol of faithfulness and confidence. It has reputed healing properties, especially to increase mental capacities such as creative imagination. Black opals worn near the heart on necklaces made of gold are said to protect one from the evil eye and protect travelers on journeys to far away lands. Opals have been ground up and used a magic potions to heal the body, ward off bad dreams, and used an energy enhancement tools.
Deposits: Most opal is found where geothermal hot springs dried up during seasonal periods of rainfall and extended dry periods. More than 90% of the world's quality gem opals come from Southern Australia, although it can be found in other parts of the world such as Brazil, Mexico, Czechoslovakia and USA (Nevada and Idaho).
All superb black stones have been obtained from the Lightning Ridge field, New South Wales, Australia. Deposits of White opal in Japan, Fire opal in Mexico and Honduras.