SiO2nH2O - Hydrous Silicon Dioxide
Opal is usually white, clear, pale red or black, and emits brilliant flashes of multi-colored light. Watching the fire in an opal is enchanting.
Opal is a non-crystalline form of the mineral silica which, despite its amorphous structure, displays an amazing degree of internal organization. Opal is related to its more commonly found but highly crystalline cousins quartz and agate, and is formed from amorphous "balls" or lumps" of silica rather that from ordered, naturally faceted crystals.
The most striking quality of opal is its ability to refract and reflect specific wavelengths of light. In fact, the term "opalescence" was coined to describe this phenomenon. The size and spacing of the amorphous spheres of silica within the stone refracts specific wavelengths of light; each sphere refracting a single, pure spectral color much like the individual microscopic droplets of water in a rainbow. The interplay of these pure wavelengths of light gives opal its unique visual appeal, and makes it one of the most sought-after gemstones in the world. More on...
Nevada's state precious gemstone is the Virgin Valley black fire opal.
Care and Treatment
Opal is a "living" stone, which means it must be protected from heat and detergents that "dry" the gem. Opals develop crazing if they are allowed to dry out. Heat treatment is catastrophic!! In addition to cracking, loss of water causes loss of iridescence.
Care must be taken when polishing and setting opals. Despite their hardness, they are prone to crazing and cracking, and loss of water content causes a noticeable loss of iridescence. To prevent this, opals are normally stored in moist cotton wool or cloth until it is time to work with them. Sometimes, an opal that has lost its opalescence may be "rejuvenated" by re-hydrating the stone with water or special oils, but this may only temporarily improve the stone's appearance.
The chemical composition of opal is SiO2H2O, silicon dioxide combined with water (an opal stone may contain up to 30% water.) The silicate minerals in the stone add to its weight, giving it a specific gravity ranging from 1.98 to 2.5 times that of pure water. Opal's scratch hardness is measured at 6.0 to 6.5 on the Mohs' scale, similar in hardness to quartz, a little more than halfway between the hardness of talc and diamond.
Specific Gravity: 2.65 - 2.66
Cherry: Red corpuscle & blood disorders; depression; apathy; lethargy; intuition & joy.
Dark: Reproductive organs; spleen & pancreas; filters red corpuscles & aids white corpuscles; bone marrow; depression, esp. of sexual origin; balances; amplifies creative & intuitive thought; grounds radical emotional body.
Jelly: Spleen & abdominal diseases; cellular reproductive problems; helps absorb nutrients; minimizes wide mood swings; mystical thought amplifier.
Light: Balances L & R brain hemispheres for neuro disorders; stimulates white corpuscles; helps bring the emotions to mystical experiences; aids abdomen, pituitary & thymus problems.
Most opal is more than 60 million years old and generally dates back to the Cretaceous period when dinosaurs roamed the earth.
It is found near the earth's surface in areas where ancient geothermal hot springs once flowed. The minerals bubbled up from beneath the surface of the earth and slowly, over the centuries, lined the walls of cracks, vents and underground cavities in the bedrock. Most opal is found where geothermal hot springs dried up during seasonal periods of rainfall and extended dry periods.
The story of opal inn Australia begins more than million years ago when the deserts of central Australia were a great inland sea, with silica-laden sediment deposited around its shoreline. After the sea receded and disappeared to become the great Artesian basin, weathering 30 million years ago released a lot of the silica into a solution which filled cracks in the rocks, layers in clay, and even some fossils. Some of the silica became precious opal. Opal is one of the few gemstones that is sedimentary in origin. The water in opal is a remnant of that ancient sea.
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 Nevada. All black opals come exclusively from Australia. Opal is found in Australia, Brazil, Czechoslovakia, Mexico and USA (Idaho).
April: Mystical Birthstone
June: Other Birthstone
October: Modern and Ayurvedic Birthstone
Star Stone Months
- High quality opal is more valuable than diamond; up to $20,000 per carat.
- Some people think the opal is bad luck when worn if it is not your birthstone. This is not true. The story was started by Sir Walter Scott in his novel Anne of Gierstein, in which the heroine of the novel has her life force caught in the beautiful opal she wears and she dies when the fire in the opal is extinguished.
- In ancient times opal was accepted as a symbol of faithfulness and confidence.
- The name "opal;" is derived from the Latin word opalus, meaning seeing jewel.
- The Arabs believed that opals fell from heaven in flashes of lightning, and that's how they received their fiery color.
- Opals are very powerful in ritual magic. Since a quality opal contains every color of every other birthstone, it can be used or charged with all the energies and powers of the other stones combined and can be used in place of any birthstone for spells, rituals or other magical needs. Opals have been linked to invisibility and astral projection. and have been used to recall past lives (each color supposedly represents a past life).
- It has reputed healing properties, especially to increase mental capacities such as creative imagination and other unused powers of the mind.
- Fire opals are often used in money rituals to draw funds to those who are in need, normally worn as a pendant on a gold necklace, one surrounded with 10 or 12 small diamonds is said to have excellent money drawing power.
- Black opals are the tools of choice for witches and magicians, who use them primarily to enhance their magical receptive or projection powers. Black opals worn near the heart on necklaces made of gold are said to ward off evil, 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.
- The white opal, when used in rituals on the full moon night, is said to bring the moon goddesses' powers to full fruition in the practitioner.
- Archaeologist Louis Leakey found six thousand year old opal artifacts in a cave in Kenya!
- The Aztecs mined opal in South and Central America.
- Opal was also treasured in the Middle Ages and was called ophthalmios, or "eye stone," due to a widespread belief that it was beneficial to eyesight. Blonde women wore opal necklaces to protect their hair from losing its color.
- 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. Napoleon gave Josephine a beautiful opal with brilliant red flashed called "The burning of Troy,"