There are colorful gemstones, and then there is opal.

October’s birthstone is famous for its extraordinary play-of-color—a shifting display of blues, greens, pinks, oranges, yellows and reds that seems to change every time the stone moves. No two opals are exactly alike, making each one feel wonderfully individual.

For October birthdays, opal is a fitting birthstone: distinctive, a little unexpected and impossible to overlook.

What Makes Opal So Unique?

Unlike many gemstones, opal does not get its beauty from facets or a single saturated color. Its signature appearance comes from its internal structure.

Opal is composed of hydrated silica. In precious opal, microscopic silica spheres are arranged in a way that causes light to diffract as it passes through the stone. The result is the flashes of spectral color known as play-of-color.

Move an opal slightly and an entirely different combination of colors may appear. This phenomenon is part of what makes fine opal so captivating—and why every stone is truly one of a kind.

Not all opal displays play-of-color. Common opal, sometimes called potch, may be beautiful in its own right but does not exhibit the same shifting rainbow effect associated with precious opal.

Opal Comes in More Than White

Classic white opal may be the variety most people recognize, but the opal family is surprisingly diverse.

White opal has a light or white body color with flashes of color throughout. Black opal has a dark background that can make its play-of-color appear especially dramatic. Fire opal is known for warm yellow, orange and reddish body colors and may or may not display play-of-color.

There are also opals with blue, green and other body colors, as well as stones whose patterns and color combinations are completely their own.

That variety is part of opal's charm. Choosing one is less about finding the "perfect" opal and more about finding the one that catches your eye.

The History and Meaning of Opal

Opal has inspired fascination for centuries. Its rainbow of colors led ancient cultures to associate it with other precious gems, believing a single opal could hold the colors—and perhaps even the qualities—of many gemstones at once.

Throughout history, opal has been connected with hope, creativity, love and good fortune. Its changing colors have also made it a symbol of individuality and imagination.

Opal is traditionally associated with October and is also given to celebrate the 14th wedding anniversary.

And despite an old superstition suggesting opal could be unlucky, its much longer history tells a very different story. For centuries, opal was treasured as a stone of luck and extraordinary beauty.

Where Do Opals Come From?

Australia has historically been one of the world's most important sources of precious opal and is particularly famous for white and black opals.

Today, beautiful opals also come from Ethiopia, Mexico and other locations around the world. Mexican deposits are especially well known for fire opal, while Ethiopian opals have become increasingly prominent in the jewelry market.

An opal's origin can influence its appearance and characteristics, but beauty ultimately comes down to the individual stone.

What Makes an Opal Valuable?

Because opals vary so dramatically, evaluating them is different from evaluating many other gemstones.

Several factors can affect an opal's beauty and value, including its play-of-color, pattern, brightness, body color, transparency, size and overall condition.

Color is especially important. Bright, vivid flashes that appear clearly as the stone moves can be highly desirable. Red is relatively rare in play-of-color and can contribute significantly to value, particularly when combined with other vibrant colors.

Patterns matter, too. Some opals show broad patches of color, while others display tiny pinpoints, rolling flashes or distinctive mosaic-like arrangements.

With opal, the stone itself tends to make the introduction.

Opal Jewelry: Made to Stand Out

Opal lends itself beautifully to jewelry because every stone brings something different to the design.

Opal pendants and earrings showcase the gemstone's color while offering a little more protection from everyday bumps. Rings can be spectacular, but because opal is softer than gemstones such as diamond, ruby or sapphire, they require more mindful wear.

Opal also pairs beautifully with diamonds. The crisp brilliance of diamonds creates a striking contrast against opal's softer, shifting colors.

Whether the style is vintage-inspired, modern or completely unexpected, opal has a way of becoming the focal point.

How to Care for Opal Jewelry

Opal ranks approximately 5 to 6.5 on the Mohs scale of hardness, so it requires a little more care than harder gemstones.

Avoid exposing opal jewelry to harsh chemicals, extreme heat or sudden temperature changes. Remove opal rings before strenuous activities, cleaning or situations where the stone could be knocked against a hard surface.

For routine cleaning, use a soft, damp cloth and mild soap when appropriate. Avoid ultrasonic and steam cleaners unless a jewelry professional has specifically determined they are safe for the piece.

When you're unsure, professional cleaning and inspection are the safest choices.

Choosing an October Birthstone That's Completely Your Own

Perhaps the best thing about opal is that there is no single version of it.

One stone may glow with cool flashes of blue and green. Another may suddenly reveal red, orange and gold. Some are subtle; others put on quite a show.

That individuality makes opal particularly meaningful for an October birthday, anniversary or simply for someone who loves jewelry that doesn't look like everyone else's.

At Roman Jewelers in Bridgewater, New Jersey, our jewelry specialists can help you explore opal jewelry and find a piece with the color, character and style that speaks to you.

Because when the gemstone itself is one of a kind, the jewelry should feel that way, too.

Frequently Asked Questions About Opal

What is the birthstone for October?

Opal is one of October's traditional birthstones. Tourmaline is also recognized as an October birthstone.

What gives opal its rainbow colors?

Precious opal contains microscopic silica spheres that interact with light, producing the shifting spectral colors known as play-of-color.

Are all opals rainbow colored?

No. Precious opal displays play-of-color, while common opal does not. Opals also occur in many different body colors and appearances.

What does opal symbolize?

Opal has historically been associated with hope, creativity, love, imagination and good fortune.

Is opal unlucky?

The idea that opal is unlucky is a relatively modern superstition and conflicts with much of the gemstone's earlier history. Opal was prized by many cultures and was often associated with good fortune.

Where are opals found?

Australia is historically famous for precious opal, while Ethiopia and Mexico are also important sources. Opal is found in several other locations around the world.You can explore more about October’s opal birthstone and its origins at GIA

Is opal durable enough for everyday wear?

Opal can be worn regularly, but it requires more care than harder gemstones. With a Mohs hardness of approximately 5 to 6.5, it can be scratched or damaged by impact.

Can I wear an opal engagement ring?

Yes, but an opal engagement ring requires more mindful care than a diamond, sapphire or ruby ring because opal is softer and more vulnerable to scratching and impact.

How should I clean opal jewelry?

Gentle cleaning with a soft cloth and mild soap is generally safest. Avoid harsh chemicals, high heat and aggressive cleaning methods, and have valuable opal jewelry professionally inspected and cleaned when needed.GIA offers an excellent Opal Care and Cleaning Guide

What anniversary is associated with opal?

Opal is traditionally associated with the 14th wedding anniversary.