Opal is an incredibly unique stone that has been named the queen of gems by the ancient Romans because it contains all the colors of the other gems. The name comes from the Sanskrit term "upala", which means "precious stone."
Opals have historically been considered a very lucky and powerful stone. It was said to contain the powers of all the other stones, due to its array of colors. Opal is a stone of inspiration, it brings deep emotions to the forefront, releasing inhibitions and granting its wearer increased confidence and openness. It also helps to focus mental capabilities and provide motivation and energy. This has been said to be a very spiritual stone, it wards off the evil eye and brings happy dreams while blocking bad dreams from your psyche.
In 1872, a new source for opal was discovered in Australia. These opals were much more beautiful than those discovered before and has since then dominated the world markets, and are what pushed an increasingly high demand for this stone. The incredible display of colors has been a mystery until relatively recently. With the use of an electron microscope, studies show that opals consist of transparent spheres of silica that are tightly packed. The spaces between these silica spheres contain only air and water. In precious opal these spheres are uniform in size and precisely packed into an orderly three dimensional arrangement. The diffraction of light and iridescence that creates the beautiful look of opal that we know today only occurs if the silica spheres are of the correct size and are precisely arranged. In lesser quality opal the silica spheres are poorly shaped, of incorrect size, and/or not arranged in a regular pattern. This stone can form only when an undisturbed space in a rock holds a clean solution of silica from which water is slowly removed over thousands of years.
Opals vary according to transparency and body color. Prices are very subjective, as no two opals are exactly the same.
White opal (Figure #1): Translucent stones with color play against a white body color, these are most common. Milky white stones with little color play are used in budget jewelry, while finer quality with higher color play can go for $200 to $300 dollars per carat.
Black opal (Figure #2): Stones with a very vivid play of color and iridescence against a black or dark body color. These highly prized stones are a fairly new discovery and were unknown before the discovery of the legendary Lightning Ridge opal field in Australia in 1903. This discovery has caused the demand of this stone to skyrocket. Today top grade black opal can sell for $15,000 a carat. Some exceptional stones have even sold for $20,000 a carat.
Crystal opal (Figure #3): This stone is white and very transparent. It's more valuable than white opal and has a lot of bright colors and iridescence. The difference between white and crystal opal is white opals have a milky look, where crystal opals are more transparent and have more vibrant color play. Crystal opal is similar to black opal but is light and more transparent. In its highest qualities, it is valued at more than $2,500 per carat.
Fire opal (Figure #4): These stones are transparent or semitransparent, resembling gelatin, with orange, yellow, or red body color with or without play of color. They are sometimes called Mexican opals because most of the best fire opals are found in volcanic rock in Mexico. This stone is commonly faceted due to its transparency. The most prized fire opals are reddish orange, transparent and have play of color within the stone; this quality can retail for as much as $300 per carat. Lower quality stones that are translucent and yellowish or brownish in color may sell for around $5 per carat.
Boulder opal (Figure #5): Found in rock formations, specifically ironstone. The opal often forms in small layers within fractures on the surface of the rock. Rare gem quality boulder opal can sell for $3,000 to $20,000 per piece, but you can get attractive stones for a few hundred dollars.
Doublet opal (Figure #6): This is a manmade combination of a small layer of natural crystal opal glued on top of ironstone. Against the dark surface, it looks like black opal. Doublet opals are significantly less expensive than black opal, but achieves a similar look. The main difference is doublets are almost always flat, but black opals are domed and smooth with no facets. This cut is called cabochon; almost all natural opals are cut this way. These range in price from $200 to $1,000 per piece.
Opal has a mohs scale of 7, but you must be careful with this stone due to its chemical structure. This stone is very sensitive to sudden change in temperature. Never clean your opal in an ultrasonic cleanser as it could crack the opal. It is recommended that your opal be worn frequently, the moisture from the wearers skin helps preserve the stone and prevent it from cracking.
With its multiple benefits and unique beauty, It is no wonder opals have been prized for centuries. What do you find most interesting about this stone? Which variation of opal strikes you the most?
Pictured is a 5.6 carat natural black opal from lightning ridge in platinum and diamonds. Ring was designed by Alex Gulko in 2009.
By Viktoriya Gulko
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