Opal mineral
Among all the variety of opals, the main factor in determining the value is the brightness of the play of shades within it. Another factor is the opal mineral colors and patterns that are created by the play of light. Black opal is especially popular for its delightful inner crimson sheen in night-black stone. This opal is rare and very expensive. Another rare variety of opal is “harlequin”, its color scheme resembles a chessboard.
Among the expensive opals, stones with a maximum of red color are most valued. Opals with strong shades of blue or green are no less beautiful, but they are much more common.
At the end of the 18th century, the great gem expert Brickman wrote: “It is much easier to find a few hundred of the best diamonds than a dozen opals without any blemish.” Many connoisseurs of precious stones put this stone in first place among the gems in terms of value. Even the famous Roman commander Mark Antony failed to take the opal ring from the disgraced Senator Nonius in pain of death – it cost a fortune. The famous opal “Burning Thunder”, bought by Napoleon for 30,000 gold ducats, was presented to his wife, Josephine. The Queen of Great Britain Victoria and the Russian Empress Alexandra Feodorovna were always involved with opal jewellery.
In the form of a talisman, opal guarantees success in all endeavors, but only on the condition that its owner is a noble person who has managed to overcome selfishness and a thirst for money in himself. Opal mineral is able to bring the gift of prophecy, but only if the prediction was not intended to harm anyone. For these reasons, it was believed that this stone can only be worn by people with pure thoughts. In the East, opal was a stone of fidelity and hope.
Opal as a talisman protects the wearer from depression, sadness and melancholy, infectious diseases, and also calms the nerves. Opal keeps you from base passions, whims and irritation. The owner of the opal is not afraid of the intrigues of enemies.
Color: brown, yellow-brown, brown-black (regular opal), brown-red, red, green, yellow with a green tint (prazopal or chloropal), colorless (chiolite), light (milky opal or cacholong), orange-red , blue, yellow with an orange tint, iridescent (noble opal), textured opal with natural remains, banded, spherical.
Transparency: transparent, translucent, opaque.
Luster: glassy, greasy, pearlescent.
Hardness: 5.5-6.5.
Color: due to impurities of iron, chromium, nickel, copper, manganese and other inclusions.
Prevalence of opal mineral:
Opal is created in the bowels of the earth from a liquid mass of silica, which, in the process of solidification, retains a small amount of water in its composition. If you place an opal under a microscope, you can see its internal structure, which is located in a prescribed order (like a honeycomb) in a set of silica gel, small identical balls of silica. This structure provides an iridescent play of colors, which changes with the rotation of the stone. Opal deposits can be found all over the world. Common and wood opal can be found in India, Mongolia, USA, Indonesia, Iraq, Australia, Slovakia, and the Czech Republic. Opal deposits are also found in other countries of the European continent – in Hungary, Romania, Serbia, Montenegro, Poland, Ireland, France and Bulgaria. The most valuable is noble opal. About 90 percent of its production comes from Australia. Black opal is mined exclusively in Australia at the famous Lightning Ridge deposit, as well as at the Minntabie deposit. The Andamooka deposits and several deposits in western Queensland are also known. Mexico is one of the main producers of multicolored noble opals. There you can find stones of red, blue, green colors, as well as varieties such as “fire” opal and gyrasol. Deposits of “fire” opal are known in Kazakhstan.
finishing: cut, cabochons, engraving, doublets, triplets, stone carving.
similar minerals: agate, hyacinth, onyx, ivory.
Care of opal:
long exposure to the sun is contraindicated for opal – it dehydrates, loses its iridescence, becomes milky white. It must be protected from sudden changes in temperature, as this can cause cracking due to the large amount of moisture contained in the opal. This stone should be protected from impact and from the effects of abrasive substances; clean only in soapy water; ultrasonic and steam treatments are prohibited. Check the variety of cuts for this beautiful stone.