Opal meaning: the play-of-color October birthstone

How the colors appear

Precious opal is made of microscopic silica spheres stacked in orderly layers, which diffract light into spectral flashes known as play of color. Opal holds a good amount of water, often several percent, and its silica is amorphous, so it has no crystal structure. Strictly speaking it is a mineraloid. Common opal, without play of color, also exists and is sold as simple colorful stone.

What it is traditionally associated with

In crystal culture, opal is linked with creativity, imagination and change, and some people connect it with the crown chakra. As the October birthstone, it is a favorite birthday gift. Old European folklore called it unlucky for a time, a superstition often blamed on a 19th century novel. All such stories are cultural, not factual.

Everyday ways to use it

• Wear it as a pendant or earrings, which expose it to fewer knocks than a ring.
• Place a small piece near your art or writing space.
• Give it for an October birthday.
• Admire it in daylight and lamplight; the colors change with the source.

Care and cleaning

Opal needs gentler handling than most gems. Do not soak it in water for long, and keep it away from hot, dry places, since losing water can lead to cracking, known as crazing. Do not leave it on a sunny window or near a heater. Wipe it with a soft damp cloth, avoid ultrasonic cleaners and steam, and store it wrapped, ideally apart from harder stones.

Real or fake?

Doublets and triplets, where a thin slice of opal is glued to a backing, are legitimate but should be labeled as such. Synthetic and imitation opals have a very regular, honeycomb-like pattern of color under magnification. Ask for clear disclosure of what you are buying.