Opal is the October birthstone as well as the accepted anniversary gemstone for the 14th year of marriage. The well-known Roman naturalist Pliny described opal as "made up of the glories of the most precious gems... the gentler fire of the ruby, the rich purple of the amethyst, the sea-green of the emerald, glittering together..."

White opal has a white or light body color with flashes of many colors.

Black opal has a black, dark blue, dark green or gray body color with vivid flashes of color such as red, pink and bright green.

Opal has symbolized hope, innocence and purity through the ages. In the Middle Ages, young, fair-haired girls wore opals in their hair to protect its lovely blond color.

Medieval writers believed opal could render its wearer invisible when the need arose. It was also said to have a beneficial effect on eyesight. It was thought to banish evil spirits and favor children, the theater, amusements, friendships and feelings.

Care should be taken to protect it from scratches, sharp blows, household chemicals, and extreme temperature changes. To maintain the brilliance of opal, it should be wiped clean with a soft cloth, or washed gently in Original Diamond & Precious Jewelry Cleaner. Do not use a home ultrasonic machine.

Opal sources are Australia, Mexico and the U.S. Sometimes tourmaline is used as a birthstone for October and spans the spectrum from red to violet. It also occurs in color combinations in one stone which accounts for its popularity. It is not as fragile as opal and is sometimes selected by those who prefer faceted stones.