The name opal was derived from the Sanskrit "Upala" and later the Greek derivative "Opallios," meaning to see a change of color. Opal is a gemstone that ranges from semi-transparent to opaque. Its body color covers a broad spectrum of colors, but is mostly prized for what is known as play of color, the ability to reflect and refract light into flashes of multiple colors.
Historically, Scandinavian women wore opals as hair ornaments to prevent their blonde locks from going gray. The Arabs thought that opal would ward off lighting and give a cloak of invisibility to its wearer when desired. It was supposed to grant vigor, aid the heart and kidneys and protect against fainting and infection.
Opals were also mined by eastern Europeans, the Aztecs of Central America, and ancient tribes in Central Africa. An opal was featured in the crown of the Holy Roman Emperor, and is still among the crown jewels of France. Napoleon gave Josephine an opal, and Queen Victoria was known to give them out as wedding presents. Opals are mentioned in the plays of Shakespeare and the novels of Sir Walter Scott.
Several opals are worthy of mention, including the 77-carat opal of Louis XVIII, kept in the National Museum of Natural History in Paris, and the 203-carat opal presented by the Australian government to Queen Elizabeth II of England in 1954.
In addition to its place as Octobers birthstone, opal is also a recommended gift for couples celebrating their 14th wedding anniversary.
Opal: Most opal is 50-65 million years old, dating back to the time of dinosaurs in the Cretaceous period. Opal formed as silica from decomposing rocks that mixed with ground water and formed a silica gel that hardened in underground cavities and fissures.There are two distinct types of opal, common and precious. The way the silica particles form determines which type. In precious opal, silica particles are packed in regular rows and layers. Moving the stone causes light to diffract, or split, as it grazes the opal surface. This light diffusion shows iridescent flashes of green, blue, aqua and sometimes yellowish or red colors which are referred to as "fire". Opal is found in a wide range of colors including: green, blue, aqua, and pink. See opal varieties and boulder opal for more in depth discussions about this wonderful gemstone.
