Precious opal is the only opal gemstone that flashes color. The flashing color of the precious opal has been seen as a phenomenon, but there is a reason why the opal flashes color. The precious opalâ€™s structure consists of numerous spheres of silica, hydrous silica, and water packed together in a pattern to form layers. The refraction of light, back and forth, between the opalâ€™s layers causes the light to break up into spectral colors. The unequal refraction of different wavelengths of visible light will cause bright flashes of different prismatic colors. The sizes of the spheres determine which colors are visible from the precious opal. Particles that are large enough to allow the longest wavelengths of visible light through the gem will allow all of the colors of the spectrum to be seen.
If the particles are small and shorter wavelengths of visible light pass through, then the only the colors produced by the shorter wavelengths will be able to be seen. The precious opal exhibits flashes of rainbow-like colors when it is viewed from different angles. The many opal colors have many different tones. The opals may have a light or dark body color that may be translucent or transparent. Opals that are seen in jewelry have a milky-white base with varying flashes of color. The most rare and expensive opals are black opals, which have a body color that range from dark gray to black with fiery flashes of color.
The precious fire opal is often an alternative to the black opal. Fire opals have base colors ranging from yellow to orange; these colors can be transparent to translucent displaying fiery flashes. The fire opal is most commonly known for its fiery red color, and not the flashes it displays. This opal is usually sold for its color and clarity, but it is not flash as many colors at other opals. It is also less expensive than the black opal.
The number of colors exhibited and the evenness of the pattern judge the quality of the opal. The cheapest opals are the jelly or water opals. Water opals are colorless, transparent or semi-transparent, and have little or no play of color. The fire opal is inexpensive, but it is more expensive than the water opal. The opal is often cut into a dome shape and set in earrings, pendants, bracelets, and pins. When set in pieces of jewelry, the opal may be joined by rubies, sapphires, or emeralds that help enhance particular flashes of color. The best opal pieces may be surrounded by small diamonds and other beautifully colored gems. There are also some opals that may be fashioned into beads, and widely sold to women and young girls.
Precious opals are gemstones that are usually found in sandstone or claystone. Opal deposits are spread over a wide area, but there arenâ€™t many that aware of their location. Mining is often done on a small scale with hand-operated machinery and small tools. It is possible to loosen an opal from its host rock. The most important source of opal is Australia. However, the fire opal is often found in Mexico, and is often known as the Mexican Opal.
There are also many opals found in Africa, the United States, Brazil, and areas of the former Soviet Union and Nicaragua. Opals are also sensitive and can be harmed be many chemicals. The gemstone should not be cleaned with ultrasonic cleaners. Cleaning an opal with oil will make the fire brighter, but it is also prohibited because it can damage the opal. It is best to periodically soak opals in water, so that they absorb lost moisture. Precious opals display flashes of color like no other gemstone. The gemstone is often used as a great addition to, bracelets, necklaces, and rings.
Please use the form below to comment on this page: