History of Opal Gemstones
From the Sanskrit word “up álá” that means stone, Greek word “òpalliòs,” and the Latin word “opalus” comes the word opal. In South Australia the official gemstone is opal. The women’s national basketball team as well as the Commonwealth of Australia is nicknamed as The Opals. While in the state of Nevada, the official state gemstone is the precious black Fire Opal - due to the black opal that was found in Humboldt County of Virgin Valley in Nevada.
Opal, according to Shakespeare, was “the queen of gems” in the “Twelfth Night”; to the Romans, this gemstone is a symbol of love and hope; and to Marbode, opal has the ability to make its wearer invisible. Opal is the traditional birthstone for the month of October.
If you wish to possesses a gem as enchanting as an opal, be reminded that this precious gem was regarded to be a provider of good luck during the Middle Ages; however, according to our modern superstition, the stone is tainted with bad luck. This bad luck is believed to be avoidable once the stone is offered as a gift to the peron that is born in October. Nevertheless, opal with its bewitching characteristics is one valuable gemstone one would be glad to possess.
Physical Properties of Opal Gemstones
Compared to common opals which are truly amorphous, precious opals contain structural elements. The water content of opal can reach up to 20% but it is usually between 3 to 10%. When it comes to the clarity of opals, it ranges from being clear through shore, yellow, red, magenta, yellow, green, blue, brown, gray, black and even white. The rarest hues of opal are black and red, while the most common are green and white.
Mineraloid gels of opals are usually deposited at temperatures. Opals commonly occur in rocks such as limonite, rhyolite, basalt and sandstone. This birthstone is an amorphous mineraloid of hydrated silicone dioxide. The term opalescence is the common description of the beautiful and unique process of opal solidification. There are also common opals in the market such as milk opal, wood opal, resin opal, hyalite, geyserite, menilite, and diatomite. Peruvian opal or the blue opal and Fire opal or Girasol are also other varieties of the gemstone. One of the most famous opals is the “Andamooka Opal that was presented to the queen of England, Queen Elizabeth II and was called the “Queen’s Opal”.
In the nineteenth century, Cervenica in Slovakia is the only mining district in Europes. Today, most of the worlds Opal is mined in Australia, in a town called the Coober Pedy. Black opals with a predominantly black background are found in New South Wales called the Lightning Ridge. Sporadically, boulder opals are found in western Queensland. While fire opals are mostly found in Mexico and Mesoamerica and white base opal comes from Spencer, Idaho. Other places around the world where there are significant deposits include Hungary, Slovakia, Czech Republic, Turkey, Honduras, Brazil, Nicaragua, Indonesia, Ethiopia, and Guatemala.