October Birthstone: Opal. October Birthstone Color is Multi-colored.

Perhaps because of the cold weather and shortening days of the month, October was a month associated with bad luck and pain. But the opal, the October birthstone, was a talisman of hope and good fortune in that late fall month. The opal, a completely unique stone with a color and properties all its own, has a symbolic history worthy of its status as October’s birthstone.

If you ask a scientist, she’ll tell you that an opal is an amorphous deposit of silica very similar to quartz, with a high proportion of water weight for a mineral of its kind. Opal, primarily a product of Australia, has a unique internal structure that allows it to diffract light. While the stone itself can be anywhere from clear to white, the refracted light can occur in a wide rainbow of colors, including red, orange, yellow, green, blue, magenta, gray, olive and even black.

But if you ask anyone who has bought the birthstone of October for herself or a loved one, she’ll just tell you that it is a unique gemstone with an almost magical display of rainbow colors. Traditionally, opals have been associated with symbolic properties like hope, innocence and purity, perhaps related to its pearly luster, as well as ideas like happiness and confidence connected to its colorful rainbow spectrum. Because of its association with the eyes and vision, opals have been used to treat eye infections, enhance vision, imagination and dreams. Of course, today few people believe that an opal can be used to improve eye health or increase confidence, but the rainbow of October’s birthstone colors is as magical as ever.

The color of October’s birthstone is hard to pinpoint. Unlike September or March, the birthstone of October can be found in almost any color. What distinguishes the opal from other stones is the unique play of color and glint of light that sets the opal part from every other gemstone. The most common kind of opal, the white opal, has a white, milky base color with a rainbow of pastel shades, while the black opal reflects blue, gray and green tones. The crystal opal is close to transparent with a bright rainbow of colors, while the fire opal is translucent with fiery sparks of red, yellow and orange. Of all these varieties, those with red sparks against black are the most rare, while white and green opals are much more common and less expensive. When set in jewelry, opals of many colors are often set against a dark stone like basalt to enhance their natural colors.

The word opal is probably derived from the Roman word opalus, but where this word comes from is unknown. The Roman writer and scientist Pliny the Elder refers to the stone, and modern historians suggest that the word may be related to the Roman goddess, Ops, wife of Saturn and the goddess of fertility. Other historians relate the word opal to the Greek opillos, which is related to the English word “opaque,” a fitting source for the opal—a stone of uniquely opaque pearly luster. A third opinion traces the word to Sanskrit, noting that opals were supplied to the ancient Greeks and Romans by Indian traders.

In the medieval period, every color of gemstone was associated with specific properties of luck and fortune. But because the opal can reflect every color in the rainbow, it was considered especially lucky. The opal was even said to confer invisibility. However, the reputation of the birthstone of October took a dip in 1829, when Walter Scott’s best-selling novel Anne of Geierstein was published. In the novel, a drop of holy water falls on an opal talisman, turning it colorless, after which the owner of the opal mysteriously dies. Scott’s book was so popular that the sale of opals dropped by 50% in the year after it was published, and remained low for a quarter of century. Meanwhile, in Russia, the opal was said to represent the evil eye and was avoided in jewelry.

However, the opal has been treasured far more than it has been feared. The ancient Romans called it “cupid paederos,” meaning “child as beautiful as love,” and ancient legend attributed the opal to a flash of lightning come to Earth. Opals were set into crowns and necklaces for kings and queens to wear to ward off evil. And today, as October’s birthstone and a popular stone for all kinds of jewelry from rings to necklaces, the opal is finding new popularity and a new appreciation for its subtle colors and unique appeal.