October Birthstone: Opal and Tourmaline Guide to Color, Meaning, Value and Care

The October birthstone is opal, and since 1952 it has shared the month with tourmaline. Opal is the traditional stone, a hydrated silica that flashes rainbow play-of-color; tourmaline is the modern alternate, a hard, faceted crystal that comes in more colors than any other gem, with pink as its birthstone color. I have set, sold and repaired both since 2016, and the choice between them is really a choice between glow and sparkle, and between a stone you protect and a stone you can forget you are wearing. This guide covers both, side by side.

What Is the October Birthstone?

The short answer, then the reason it is not shorter.

If someone asks "what is the birthstone for October," the complete answer is opal and tourmaline. Opal is the one most people know, and it is the one printed on older charts and engraved in vintage lockets. Tourmaline is the younger partner, added so that October-born buyers had a harder, more colorful option. Every major trade body, including the Gemological Institute of America and the American Gem Society, lists both.

The two could hardly be more different. Opal is not even a true crystal; it is amorphous silica with water locked inside, cut as a smooth cabochon so the play-of-color can move across the dome. Tourmaline is a boron silicate crystal that takes facets and throws light back like a sapphire. That difference explains almost everything about how each one is worn, priced and cared for. If you are new to birthstones, our hub on what is my birthstone lays out all twelve months, and the birthstone jewelry collection covers every one of them.

Opal vs Tourmaline: The Two October Birthstones Compared

The side-by-side I keep on the bench for October customers.

Put the two on a tray under the same lamp and you see the split immediately. The opal glows from inside and changes as you rock it; the tourmaline stays one saturated color and sparkles from the facets. Customers who fall for opal rarely switch to tourmaline, and vice versa, so I usually show both before we talk about settings. Both are available across the October birthstone collection, and the gemstone rings range lets you compare them against sapphire, moonstone and alexandrite in the same styles.

October Birthstone Color: White, Multicolor or Pink?

Why every chart seems to disagree.

The "october birthstone color" question has three honest answers. Birthstone charts that follow opal show October as white, because most opal has a light body, or as multicolor, because precious opal flashes every hue of the spectrum. Charts that follow tourmaline show October as pink, because pink tourmaline was the specific variety added in 1952. None of them is wrong; they are describing different stones.

In practice, the color you get depends on which stone and which variety you choose:

• White or light opal reads as milky white or cream with soft pastel flashes. It is the classic October look and the most affordable precious opal.
• Black and boulder opal read as dark gray, blue or brown with vivid flashes that look brighter against the dark body.
• Fire opal is transparent yellow, orange or red, usually with no play-of-color at all.
• Pink tourmaline runs from baby pink to hot pink; the deep red end is sold as rubellite. Our pink gemstones guide compares it with morganite and pink sapphire.
• Green, teal and blue tourmaline give October-born buyers a cool alternative; watermelon tourmaline gives both pink and green in one crystal.

If you want the birthstone to read as October at a glance, choose white opal or pink tourmaline. If you want the widest choice of color in a single birth month, October wins outright; no other month has a stone that comes in as many colors as tourmaline plus a stone that shows all of them at once. The pink gemstone jewelry, teal gemstone jewelry and white gemstone jewelry collections are sorted by color for exactly this reason.

Opal: The Traditional October Birthstone

A stone made of water, silica and an accident of geometry.

How play-of-color works

Opal forms when silica-rich water seeps into cracks and cavities and slowly dries, leaving behind microscopic silica spheres. In precious opal those spheres are all about the same size and stacked in an orderly grid, and that grid diffracts light the way a prism does. The American Gem Society notes this was only explained in the 1960s. Sphere size sets the color: smaller spheres, roughly 150 nanometers, produce violets and blues; larger ones, up to about 350 nanometers, produce oranges and reds. Red flash is rarest because large, uniform spheres are rarest, which is why a red-dominant opal costs more than a blue-green one of the same size.

Common opal, sometimes called potch, has spheres of random sizes and shows no play-of-color. Fire opal is prized for body color rather than flash. Everything in between is graded on three things: body tone (the darkness of the background, from N1 black to N9 white), brightness of the flash, and the pattern and mix of colors.

Types of opal

Ethiopian hydrophane vs Australian opal

Australia produces about 95 percent of the world's precious opal, and its sedimentary opal is stable: it does not soak up water and its play-of-color does not change when it gets wet. The Ethiopian deposit found in 2008 near Wegel Tena, documented in Gems & Gemology, changed the market because it made bright, transparent opal affordable. The catch is that most Welo opal is hydrophane: it absorbs water, lotion and oils, turns temporarily clear or yellowish, and can lose its flash until it dries out. A few pieces come back to my bench each year looking "dead" after a week of hand cream, and almost all of them recover once they dry. I set Ethiopian opal in pendants and earrings without hesitation, and in rings only for customers who understand they need to keep it dry.

Synthetic opal, doublets and triplets

Synthetic opal is real silica grown in a lab and is perfectly legitimate when disclosed; it is bright, uniform and inexpensive, and the tell is a too-regular pattern with a chicken-wire or columnar look under magnification. Doublets and triplets stretch a thin slice of real opal by gluing it to a dark base, which is how a "black opal" ring ends up priced like a white one. Both are fine for the money, but they should not be sold as solid natural opal, and they must never be soaked, because water can cloud the adhesive layer. Our opal engagement rings guide goes through how to spot each one from the side of the stone.

Natural Australian opal

Opal Engagement Rings

Australian, Ethiopian and Mexican opal in bezel, halo and vintage settings, in sterling silver, 14K gold vermeil or solid gold. From $92 (prices as of September 2026).

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Tourmaline: The Modern October Birthstone

One mineral family, every color in the box.

Tourmaline is not one mineral but a group of related boron silicates. Gem tourmaline is mostly elbaite; black tourmaline is schorl; brown and yellow stones are usually dravite. Trace elements set the color, and because the crystal grows in zones, a single stone can carry two or three colors along its length or from core to rim. Tourmaline is also pyroelectric and piezoelectric, which means it develops a weak electrical charge when heated or squeezed. Eighteenth-century Dutch traders used warmed crystals to pull ash out of their pipes, which is why an old name for it is "ash puller."

Tourmaline varieties

The Paraíba story is the one customers ask about most. Prospector Heitor Dimas Barbosa spent years digging in Brazil's Paraíba State before his 1989 find produced tourmalines of an electric blue nobody had seen. GIA later confirmed that trace copper was responsible, an element not previously recorded as a tourmaline colorant, and similar copper-bearing stones turned up in Nigeria and Mozambique in the early 2000s. True Brazilian Paraíba above a carat is priced like fine sapphire. Paraíba jewelry at everyday prices uses small stones or Paraíba-colored material, so read the listing for exactly what the stone is and where it is from.

October Birthstone Meaning, History and Lore

Two thousand years of opal, three hundred of tourmaline, and one famous mistake.

Opal meaning

Opal has stood for hope, purity and truth in European tradition for centuries, and for faithfulness in love, because a stone that holds every color was read as a stone that holds every virtue. Pliny the Elder, writing in the first century, ranked opal just below emerald and described it as carrying the fire of ruby, the purple of amethyst and the green of emerald all at once. He also recorded the senator Nonius, who chose exile over surrendering his opal ring to Mark Antony. Ancient Greeks believed opal granted foresight; Bedouin tradition held that it carried lightning and fell from the sky during storms. Modern crystal practice adds creativity, emotional balance and inspiration, associations we mention because customers ask, not because gemology can test them.

Is opal bad luck? The Anne of Geierstein myth

The "unlucky opal" idea is not ancient folklore. It traces to Sir Walter Scott's 1829 novel Anne of Geierstein, in which the mysterious Lady Hermione wears an opal in her hair that flares and then goes dark when touched by holy water, after which she dies. The book was a bestseller, and, as Rock & Gem and the gem historian George Frederick Kunz both record, the European opal trade slumped in the years that followed. Queen Victoria, who wore opals and gave them as gifts, did more than anyone to restore the stone's reputation, and the discovery of Australian opal in the late 1800s finished the job. When a customer hesitates over an opal engagement ring because of "the curse," this is the story I tell them.

Tourmaline meaning

Tourmaline's symbolism is younger and follows its colors. The Sinhalese name means "stone with mixed colors," and an Egyptian legend says the crystal passed through a rainbow on its way up from the earth's core. Pink tourmaline stands for compassion and love, green for vitality and courage, black for protection and grounding, and watermelon for balance between opposites. Because tourmaline generates a charge when warmed, older traditions also treated it as a "living" or energizing stone.

Tourmaline history in brief

Tourmaline was mistaken for other gems for most of history. A Spanish conquistador in the 1500s took green Brazilian tourmaline for emerald, and the "Caesar's Ruby" pendant in the Russian crown jewels is actually red tourmaline. Scientists only recognized it as a distinct mineral species in the 1800s. Maine's Mount Mica deposit was found in 1820, California's Himalaya mine opened in 1898, and between 1902 and 1910 the San Diego County mines shipped about 120 tons of pink tourmaline to Imperial China, where Empress Dowager Cixi prized it for carvings. Her death in 1908 and the fall of the Qing dynasty ended that boom. For the wider sweep of how gem meanings developed, see our history of gemstones.

Why Does October Have Two Birthstones?

The list has been edited four times, and October was in the second edit.

The modern American birthstone list was adopted by the National Association of Jewelers at its 1912 convention in Kansas City, and opal was October's stone on that list. In 1952 the Jewelry Industry Council of America revised it, adding alexandrite to June, citrine to November, zircon to December and pink tourmaline to October, as the International Gem Society documents. Tanzanite joined December in 2002 and spinel joined August in 2016 through the American Gem Trade Association and Jewelers of America.

The reasons for October's addition were practical. Opal is soft, sensitive to heat and dryness, and in the early 1950s good material was harder to stock than a faceted crystal. Tourmaline was durable, plentiful from Brazil and California, and came in a color that sold. Naming pink tourmaline gave jewelers a birthstone they could set in a prong ring without fear of returns. Seventy years on, the pairing has become the month's strength: October-born customers get the widest choice of any month. If you were born just across the line, our September birthstone guide and November birthstone guide cover sapphire, topaz and citrine, with jewelry in the September birthstone and November birthstone collections.

Libra and Scorpio: October Zodiac Birthstones

Month stones and star-sign stones are two different lists.

October spans two signs. Libra runs from September 23 to October 22, and Scorpio from October 23 to November 21. Zodiac stone lists are older and less standardized than the monthly list, so you will see several stones attached to each sign, but the common pairings are these:

• Libra birthstone: opal is the stone most often given to Libra, with pink tourmaline as the modern alternative; older lists also name sapphire and peridot, which belong to September and August. Opal's balance of every color suits a sign associated with harmony.
• Scorpio birthstone: topaz and citrine, the November stones, appear on most lists, and opal or tourmaline for Scorpios born in late October. Black tourmaline and black opal are popular with Scorpios who want the sign's darker mood.

My advice is simple: if your birthday falls in October, your birthstone is opal or tourmaline regardless of your sign, and a zodiac stone is an extra layer of meaning rather than a replacement. Our zodiac birthstones guide lists every sign, and the black gemstone jewelry collection is where the Scorpio pieces tend to live.

October Birthstone Durability and Care

What comes back to the repair bench, and how to keep yours out of it.

Hardness numbers only tell part of the story. Opal at Mohs 5 to 6.5 is softer than the quartz in ordinary dust, so a ring worn every day slowly loses its polish and picks up fine scratches; a re-polish at a bench takes minutes on a solid stone but can ruin a triplet. The bigger risk is crazing, a web of fine cracks that appears when the stone loses water too fast, usually from a hot car dashboard, a jeweler's torch during a careless resize, or a sunny windowsill. Once an opal crazes there is no fix. That is why my jewelry care notes for opal rings come down to three habits: take it off for hands-on work, keep it away from heat, and never let anyone resize it without unsetting the stone first.

Tourmaline at 7 to 7.5 with no cleavage is genuinely built for daily wear. The repairs I see are chipped culets on stones set too tightly and dulled facets on cheap material with fractures near the surface. Both are avoided by buying eye-clean stones and having prongs checked yearly. For a step-by-step routine covering every metal, see how to clean jewelry at home and how to care for your engagement ring.

Best settings for each stone

• Full bezel for opal rings worn daily; the metal rim takes the knocks. See bezel set engagement rings.
• Halo for either stone; the ring of accent stones adds a buffer and makes a 6 x 4 mm center read a full size larger. See halo engagement rings.
• Kite and geometric cuts work surprisingly well with opal because the flat facets show the flash in bands; our kite cut opal engagement rings are built on that idea.
• Crushed opal inlay in tungsten or black ceramic bands is how opal becomes a men's ring; the resin-sealed inlay is far tougher than a cabochon. See men's inlay wedding rings and opal wedding bands.
• Prong solitaire is fine for tourmaline and only for opal pendants and earrings, where nothing hits the stone. Compare formats in our styles and setting types guide.

Featured collection

October Birthstone Jewelry

Opal and tourmaline rings, couples sets, pendants and earrings in sterling silver, gold vermeil, tungsten and solid gold. From $92 (prices as of September 2026), with free U.S. shipping.

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How to Buy an October Birthstone

Eight checks, in the order that saves the most money.

1. Decide glow or sparkle. Opal for play-of-color, tourmaline for saturated faceted color. Everything after this follows from it.
2. For opal, ask "solid, doublet, triplet or synthetic?" Look at the side: a flat dark layer with a razor-straight join means doublet; a clear dome on top means triplet. Ask the seller to state it in writing.
3. Ask where the opal is from. Australian means stable; Ethiopian means bright and affordable but hydrophane; Mexican fire opal means body color rather than flash. All three are fine when priced accordingly.
4. Judge opal face-up under one soft light. Brightness first, then how much of the stone flashes, then color mix (red and orange rarest), then pattern. Ignore photos taken under moving spotlights.
5. For tourmaline, buy color before size. Medium to medium-dark saturation without gray or brown. Hold it away from the lamp; a stone that goes dull at arm's length will disappoint on the hand.
6. Check clarity by eye, not by loupe. Rubellite and watermelon tourmaline are Type III gems in the GIA clarity system, so inclusions are expected; other tourmaline is Type II. Eye-clean is the target, not flawless. Ask whether rubellite has been clarity-enhanced and whether pink stones were irradiated.
7. Match the metal. Rose gold warms pink tourmaline and fire opal; white metals keep blue and green flash crisp; yellow gold gives white opal a vintage look. See the precious metal guide and our note on what gold vermeil is.
8. Read the return and warranty terms. Opal is a stone people change their mind about once they see it in daylight. Our returns policy allows 14 days and one free size exchange, and solid gold and platinum pieces carry a limited lifetime warranty (details on the warranty page).

Two more things I tell every October customer. First, the ring size: opal cabochons sit in closed backs, so a resize is a bigger job than on a diamond ring; measure carefully with our find your size tools before ordering. Second, if you want a stone we do not stock, the custom ring page lets you send a loose opal or tourmaline, or pick one from loose gemstones, and we quote within two days. For deciding between these and harder stones, the page on the best gemstones for engagement rings ranks every option by wearability.

October Birthstone Price Logic

What moves the number, from a $92 silver ring to a five-figure black opal.

The pattern is the same for both stones: color intensity and the fraction of the stone that performs matter more than carat weight, and origin adds a premium only at the top. Because so much good opal and tourmaline is affordable, the metal often decides the final price. At Aquamarise, October birthstone pieces start from $92 in sterling silver (prices as of September 2026); solid 14K and 18K gold and platinum are made to order in three to six weeks, and interest-free Pay in 4 plus monthly plans are available through our financing page. An independent appraisal is available on solid gold and platinum pieces. Compare metal costs in yellow gold vs white gold vs rose gold.

October Birthstone Gifts, Anniversaries and Jewelry Ideas

Who the gift is for decides the stone and the piece.

For a birthday, I lean toward a pendant or earrings for opal and a ring for tourmaline, simply because those are the pieces that come back looking new years later. Complimentary laser engraving inside most rings (a date, initials or a short line up to 16 characters on women's rings and 25 on men's) turns a stock piece into a personal one; engraved pieces are final sale, so check the size first. Every order ships free in the U.S. and leaves in one to four business days when ready to ship. Browse birthday gifts by birthstone, gifts for her and promise rings for more October ideas, and the opal jewelry collection for every opal piece in one place.

October Birthstone FAQ