All about Opal
Legend has is it that the creator came down to Earth on a rainbow, to bring the message of peace to all humans. The very spot, where his foot touched the ground, became alive. The stones his feet touched started sparkling in all colours of the rainbow. These stones are believed to be the birth of opals. There are numerous legends and tales surrounding this colourful gemstone. The tale stated above was traced far back as the ancient dream time of the Australian aborigines.
All the different Opals share one characteristic in common; they shine and sparkle in a continually changing play of colours consisting of iridescent colour flashes that change with the angle at which the stone is being viewed, which experts describe as “opalescene”. Fine examples can be more valuable than diamond. The intensity and distribution of the colour flashes is a determining factor in the value of an Opal. Opals are differentiated based on their place of occurrence, and colour of the main body. Opal are found in many colours such as Black Opal, White Opal, Crystal Opal, Boulder Opal, Fire Opal, etc. Opal variations are practically unlimited. They all show in their special way unique play of colours. The exception to this is the Fire Opal; due to its transparency. Opals lacking the unique play of colours are called “Common Opal”.
The word Opal is derived from the Sanskrit word “Upala”, meaning “Valuable Stone”, the Greek term “Opallios”, which translates as “colour change” or the Latin term “Opalus”, a “stone from several elements”. Maybe Sanskrit, Greek and Latin come from a common language that has now been forgotten, but that a different topic all together that won’t be covered in this article.
Up to the first half of the 19th century, Opals were relatively rare. In the era of Art Deco the Opals with the combination of enamel experienced their flourishing, with contemporary gemstone artists preferring them to all other stones because of their subdued charm.
No one knew what caused the opalescene effect until the 1960’s; where a team of Australian scientists analysed Opals with an electron microscope. The scientists discovered that small spheres of from silica gel caused interference and refraction manifestations responsible for the opalescene effect. When the spheres are arranged in a more compact structure it causes the light to dissect on its passage through the stone creating all the colours of the rainbow.
To create the opalescene effect, Opals are cut and polished into round cabochons, oval cabochons or any other softly domed shape.
Opal loves to be worn on the skin. This is due to the fact that Opals always contain water – usually between 2 and 6 percent – making opal easily brittle if stored too dry or exposed to heat over a long period of time. This will cause the stone to show fissure and the play of colour will become paler. It is recommended that Opal be worn as often as possible, for then the gemstone will receive the needed humidity from the air and from the skin of the wearer.
Opal is an amorphous form of silica. Opals are not very high on the Mohs scale: only achieve 5.5 to 6. To combat this, thin layers of Opal are glued onto a base material known as a doublet. Gemstones like this are considerably cheaper than a solid opal, but provide the same amount of play of colour. Doublets are sometimes coated with a thin layer or dome of clear quartz – known as triplet – to make them more resistant to scratches.
For ages people have believed in the healing power of Opal. It is reported to be able to solve depressions and to help its wearer find the true and real love. Opals are supposed to further enhance the positive characteristics for people born under the zodiac sign of Cancer. Black Opal is recommended to those born under Scorpio, and Boulder Opal is the lucky stone for Aries.