October Birthstones: Opal and Tourmaline

Ethiopian Opal at Faye's Diamond Mine
This Fire Opal was taken from the volcanic slopes of an Ethiopian mountain range. It was part of our colored gem exhibition courtesy of Artinian Gems.

Shakespeare called opal “the queen of gems.” Queen Victoria’s love of opals started a major fashion trend around the turn of the century.

Opal has an especially fascinating folklore. It’s been said that the opal contains all the other gemstones, which explains the vast number of magical properties attributed to it over the centuries. They range from easing childbirth to granting the wearer a makeshift “invisibility cloak.” But above all, it is universally recognized as a symbol of hope and love.

Opals are silica-based precious stones that contain compressed water. Internal characteristics like gas bubbles, traces of other minerals, or even organic materials trapped inside result in the fascinating flashes of light and color that make this stone so popular.

95% of opals come from Australia, making it the country’s national gem, but they are also found in Central America, Japan, Ethiopia, and even parts of United States.

Types of opal

Opal Triplet - WikipediaIn general, the more color an opal has, the greater its value. White opal is the most common. Its color is similar to mother of pearl, with faint color patches on a milky background. Crystal opals are rarer and have a smooth, lustrous finish. Australia’s black opals are the most desirable of all, with their striking brilliant colors. (See fascinating footage of Faye exploring the premier Lightning Ridge opal mine in New South Wales…)

A doublet (pictured right) is an opal veneer over a dark background that enhances its color. A “triplet” is a doublet capped with a transparent crystal dome.

Special care

Care for opals in much the same way as you treat pearls. Avoid acids and solvents, prevent sharp blows and scratches, and clean frequently with a soft, moist cloth.

GIA: All About Opals

Alternative Birthstone: Tourmaline

Faye's Diamond Mine Estate Sale 2012Tourmaline is a complex mineral crystal whose composition determines its color – in fact it’s one of the only gemstones available in all the colors of the rainbow. If October is your month, you can take your pick of colors from the huge tourmaline palette – though the pink and green varieties are traditionally the most prized.

Tourmaline has very unusual reactions to heat and pressure. They are piezoelectric – taking on a static charge under friction. Many are also pyroelectric – when heated, their atomic structure becomes polarized so that they carry a low electric voltage.

Sometimes called the “peace stone,” it’s also a symbol of hope like the opal. It is believed to bestow the wearer with energy, creativity, and romance.

An incredibly rare and striking tourmaline is the variety known as Paraiba tourmaline – a breathtaking vibrant aqua color that is one of the most highly prized colored gems. The largest of these known is called “Ethereal Carolina Divine Paraiba,” weighing nearly 200 carats and set in a priceless gem-encrusted necklace.

Photo courtesy of Kaumann de Suisse via KaterinaPerez.com
Kaufmann_Paraiba_Necklace

GIA Guide to Tourmaline

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