Boulder Opal

Distinguished for its play-of-color, opal displays a brilliant range of rainbow-like colors when seen from different angles. Veins of precious opal are sometimes found running through ironstone: this is known as boulder opals. It is often striking in beauty yet more durable than other forms of opal. Opal was once considered a symbol of fidelity, assurance, and religious devotion. The ancient Roman historian, Pliny the Elder, suggested the opal is difficult to describe because it blends so many colors in a brightness that is incredible. Australia is the primary source of opal.

The gemstone Opal is the official October birthstone as adopted by the American National Association of Jewelers in 1912. It is also the birth stone for the Zodiac sign of Libra. See the birthstone tables for additional references to this stone.