by Ann Hudson
October's birthstone is the opal. Ancient Romans called the opal the "queen of gems" and saw the stone as a symbol of purity and hope. The ancient Greeks believed that opal jewelry gave the power of prophecy to its owner. Opals are considered by many to be one of the precious gems, and October birthstone opal jewelry is a wonderful way to add some decadence to any outfit. With their beautiful iridescence and shining, changing colors, opals are perfect for all types of October birthstone jewelry, including rings, earrings and bracelets.
Characteristics: The opal is a form of the mineral silica and has a rating of 6 to 6.5 on the Mohs Scale of Mineral Hardness. This makes opals fairly soft compared to other gemstones, so opal birthstone jewelry should be treated with care. Although the opal is not a crystal, it is related to the crystalline gems agate and quartz. It's commonly found among sandstone, rhyolite, basalt and limonite.
Color: At first glance, an opal might appear to be milky white to almost clear in color. With movement, however, the October birthstone displays a wide variety of hues. An opal's play of color depends on the size of submicroscopic spheres within the stone. You can choose from many different types of opals. The fire opal, for example, appears to glow with bright orange, green and blue shades. Black opals are incredibly rare and possess dark blue, purple and black hues, and the milk opal can be pale green or blue. Choose opal birthstone jewelry with stones that appeal to you.
Properties: The formation of silica particles within the stone impacts the way an opal reflects light. When the particles are packed in organized layers and rows, the stone will refract more light and have more fire. Opals are made up of 5 to 10 percent water and are therefore classified as a living gem. Heat, soap and chemicals can easily dry out an opal, and prolonged storage can also cause opal jewelry to dry out and crack. Wear your opal birthstone jewelry regularly to keep it moist and clean it with a soft cloth.
Geography: The overwhelming majority of the world's opals come from southern Australia. In fact, Australian mines provide us with 95 percent of the world's opals. Opals are also found in Nevada and Idaho in the United States and in Mexico, Brazil and Columbia.
Legends: Ancient Arab civilizations believed that opals fell to earth during flashes of lightning. Legends also state that Cleopatra used opal jewelry to gain the attention of Mark Antony. People have long believed that opals have powers, including the ability to cure mental illnesses and keep hair lustrous and blonde.
Tourmaline: Tourmalines are an alternate October birthstone. Tourmalines come in a wide range of colors, including green, brown, red, blue, pink and yellow. Some tourmalines display more than one color. Tourmalines are believed to have the power to give the wearer energy and are commonly set into rings, bracelets and earrings.