October Birthstone: Opal and Tourmaline, Explained

The October birthstone is actually two stones: opal and tourmaline. Opal is the one that flashes rainbow colours as you tilt it. Tourmaline comes in more colours than almost any other gem, sometimes pink and green in the same crystal. If you were born in October, you get the two most colourful stones on the whole list.

Why October has two birthstones

Birthstone lists have shifted over the centuries. In 1912, American jewellers agreed on a standard list so everyone sold the same stone for the same month. That list has been updated a few times since. Today the modern list gives October both opal and tourmaline, usually pink tourmaline.

Opal is the older pick. Tourmaline was added later, which gave October a tougher option. So October gets a choice: the flashy, gentle one or the tough, colourful one. You can see how the other months compare in our guide to every month's birthstone.

Opal: the October birthstone that flashes

Opal isn't a crystal in the usual sense. It's silica, the same stuff as quartz, but with no crystal structure and with water held inside. Most opal holds a few percent water by weight.

The rainbow flash has a name: play-of-colour. Precious opal is built from tiny silica spheres stacked in neat rows. Light bounces between them and splits into colours, a bit like a soap bubble. Common opal has the spheres jumbled, so it shows a soft milky colour and no flash. Both are real opal.

Opal sits at about 5.5 to 6.5 on the Mohs hardness scale. That's softer than quartz, so it scratches and chips more easily. The name likely traces back through Latin to an old Sanskrit word for "precious stone". GIA's opal guide is a good read if you want the full gem-nerd version.

What opal is traditionally linked with

Because it shows every colour at once, opal has collected a lot of folklore. The story goes that it holds the colours of all the other gems. Today people use it as a stone for creativity and self-expression, and as a reminder to let their true colours show.

Tourmaline: the second October birthstone

Tourmaline is a whole family of minerals, not just one. Its chemistry is complicated, and small changes in it give black, green, pink, red, blue and brown stones. Some crystals change colour along their length.

The best-known example is watermelon tourmaline: pink in the middle, green around the edge, like a slice of fruit. The name tourmaline is said to come from a Sinhalese word for mixed gemstones, which suits it.

Here's a cool true fact. Warm a tourmaline crystal and it picks up an electric charge at each end. The story goes that old traders used warm tourmaline to pull ash out of their pipes, long before anyone could explain it.

Tourmaline sits at about 7 to 7.5 on the Mohs scale, so it handles everyday wear well. People traditionally link pink tourmaline with kindness and love. Black tourmaline is the grounding, protective one; our black tourmaline guide covers it in depth.

October zodiac signs and their stones

October is split between two signs:

• Libra runs until about October 22. Pink tourmaline and opal are often listed as Libra stones. Browse more in the Libra collection.
• Scorpio starts around October 23. Our guide to Scorpio crystals covers the deeper, darker stones the sign is known for.

Born right on the line? Our free natal chart works out your sun, moon and rising signs from your birth time and place.

Is my opal real? Opal vs opalite

Here's the honest part. Opalite is not opal. It's man-made glass with a milky blue glow. It's pretty, it's affordable and it's popular, but it isn't a natural stone.

Our opal collection has both, side by side. Real opal pieces like cherry opal, a natural opal specimen, sit next to opalite pieces. Look for "(Synthetic)" in the product name, like the opalite bracelet. At The Rock Space, treated, dyed and man-made stones are labelled as such.

A few other things to know when you shop for opal anywhere:

• Doublets and triplets. A thin slice of opal glued to a dark backing, sometimes with a clear cap on top. They're real opal, just not solid.
• Lab-made opal. It exists and can look very regular, with a neat snakeskin or mosaic pattern.
• Glass. Opalite and other glass glows evenly and often has tiny round bubbles inside.

Raw tourmaline is less often imitated. Gem-cut pink stones are another matter, so buy those from someone who labels clearly.

Caring for opal and tourmaline

• Keep opal away from heat. Opal holds water, so a hot car, a sunny windowsill or a sudden temperature change can make it crack.
• Don't soak glued opal. Doublets and triplets can come apart in water. A damp cloth is enough.
• Store opal on its own. Harder stones, tourmaline included, can scratch it in a jewellery box.
• Tourmaline is easy. Lukewarm water and a soft cloth are fine. Skip ultrasonic cleaners for strung jewellery.

October birthstone gift ideas

A birthstone is an easy gift because the hard part, choosing, is already done. A few ideas from the shelf right now:

• A fine necklace. The watermelon tourmaline bead necklace shows pink and green in tiny beads.
• Something to collect. Raw crystals, chips and carvings in the tourmaline collection.
• Opal to hold. Real opal specimens and carvings sit beside labelled opalite in the opal collection, linked below.

Shopping for a nearby birthday too? See the September birthstone just before October, or the November birthstone just after.

Know someone with a October birthday? Make them a free October birthstone card and send it by text or email.

Frequently asked questions

What is the true birthstone for October?

Both opal and tourmaline are true October birthstones on the modern list. Opal is the older, traditional choice. Pink tourmaline is the usual second option.

Why does October have two birthstones?

Tourmaline was added to the modern list after opal. Having both gives October a choice: opal's rainbow flash, or tourmaline's colour range and toughness.

Is the October birthstone pink, sapphire or opal?

Opal and pink tourmaline. Sapphire is the September birthstone. The pink people picture for October comes from pink tourmaline.

Which is better, opal or tourmaline?

Neither is better, they just suit different people. Opal is softer and needs gentle care. Tourmaline is harder and better for rings and bracelets worn every day.

Is opalite a real opal?

No. Opalite is man-made glass with a milky blue glow. It's pretty and popular, but it isn't natural opal, so we label it as synthetic.

Come say hi

Opal's flash changes with every tilt, so it's worth seeing in person. Visit us at 396 Victoria Street North in Kitchener and hold a few before you choose. Or browse the opal collection online.