October Birthstone: Opal Meaning, Color & Jewelry
Opal is the birthstone for October, the one gem famous for its play of color, the shifting flashes of green, blue, pink, and gold that move across its surface as it catches the light. No two opals are alike. October also recognizes pink tourmaline, but opal remains its most magical emblem, a stone of creativity and imagination.
On this page
What opal means, the play of color in opal, choosing opal jewelry, caring for opal, and common questions.
| Birth month | October |
| Color | Flashing play of color over a light or dark body |
| Hardness | 5.5 to 6.5 on the Mohs scale, delicate |
| Symbolism | Hope, creativity, and imagination |
| Composition | Hydrated silica, holds water |
The meaning of October's birthstone
Because a single opal can flash every color of the spectrum, ancient writers believed it held the virtues of all other gems at once, and the Roman scholar Pliny praised it as among the most precious of stones. That sense of containing many colors in one gave opal its lasting meaning of hope, creativity, and imagination, a stone for inspiration and new ideas. Its ever shifting fire has fascinated people for centuries, and no two opals have ever shown quite the same pattern. As the October birthstone, opal brings that one of a kind, imaginative spirit to a gift.
The play of color in opal
Opal is hydrated silica, built from countless microscopic spheres packed in a grid, and it is those spheres that bend light into the flashing spectral colors known as play of color. Opal that shows this effect is called precious opal, while opal without it is common opal. The main types are white opal, with a pale body, black opal, with a dark body that makes its colors blaze and which is the most prized, boulder opal, still attached to its host rock, and fire opal, with a warm orange to red body that may or may not flash. A stone is judged on the brightness, pattern, and range of its play of color along with its body tone, and Australia remains the great source. For a closer look at what separates a fine opal, the guide to evaluating opal quality breaks it down.
Choosing opal jewelry
Look first for bright, lively play of color spread across as much of the stone as possible, in a pattern that catches your eye, since that fire is the whole appeal of an opal. Body tone matters too, because a darker body tends to make the colors blaze while a pale body reads softer. Opals are cut as smooth domed cabochons rather than faceted, so the color rolls across the surface as the stone moves. It is also worth knowing whether a stone is a solid opal or a doublet or triplet, thin layers of opal on a backing that cost less but should be disclosed. Opal pieces rotate in and out of stock, so the wider range of colored gemstone jewelry at Oath is a good place to look alongside it.
Caring for opal jewelry
Opal needs more care than almost any other gem, since it is both soft at 5.5 to 6.5 and made partly of water. If an opal dries out, or meets sudden temperature changes or harsh heat, it can craze, developing a network of fine surface cracks that cannot be undone. Never use an ultrasonic or steam cleaner or any chemical on opal; instead wipe it with a soft, slightly damp cloth and dry it gently. Store it somewhere that is not bone dry, keep it away from knocks, and choose a protective setting such as a bezel for any opal worn in a ring. Earrings and pendants ask the least of the stone. The fine jewelry care guide covers cleaning and storage for every stone and metal in more detail.
In short
- Opal is October's birthstone, the gem of play of color, tied to hope, creativity, and imagination.
- It is judged on the brightness, pattern, and range of that color, with black opal the most prized and every stone unique.
- Soft and water bearing, opal is delicate, so it needs gentle care, protected settings, and no ultrasonic cleaning or harsh heat.
Not sure which birthstone suits the person you are shopping for?
The Oath jewelry guide walks through every birth month, metal, and stone, with practical tips for choosing a piece they will keep.
Read the jewelry guideFrequently asked questions
What is the birthstone for October?
Opal is the birthstone for October, joined by pink tourmaline as a recognized alternative, though the opal remains the month's most distinctive emblem.
What is play of color in an opal?
Play of color is the flashing of spectral hues across an opal as it moves, caused by light bending through the microscopic silica spheres that make up the stone.
Is opal good for everyday jewelry?
Opal is soft and water bearing, so it is delicate and best suited to earrings and pendants, and to protected settings with gentle care when worn in a ring.
What does opal symbolize?
Opal stands for hope, creativity, and imagination, a meaning drawn from the belief that its shifting fire held the colors and virtues of every other gem.
How can I tell a natural opal from a synthetic one?
Natural opal shows an irregular, three dimensional play of color, while many synthetics show an overly regular pattern, and doublets reveal a flat join at the edge. The guide to telling genuine opal from synthetic explains the signs.
Keep reading
Opal is a one of a kind way to mark an October birthday, with hope and imagination behind its fire. Every order ships free with a 30-day return policy.
