Unpolished opal

Opal

October's birthstone

Photograph by John Cancalosi, Alamy

Represents hope

You always look at the bright side of things, seeing something good in every situation. You’re never a pessimist.

Old-school myths

Wearing an opal will make you invisible—according to legend. An opal was also believed to bring beauty, success, and happiness, as well as medicinal powers to ward off heart and kidney failure. It was once said that an opal could protect a person from lightning.

Rock-solid facts

Opals form over millions of years where hot, mineral-rich ooze—including the mineral silica—seeps into rock cracks. Tiny spheres of silica stack up and harden to become opals. The way light bounces off the silica creates an opal's colorful shimmer.