October Birthstone: Opal & Tourmaline — A Greenwood Jeweler's Guide

Most months have one birthstone. October has two — opal and tourmaline — and at Forever Jewelry in Greenwood Park Mall that's the first thing we explain when someone comes in shopping for an October birthday. Both are legitimate. Neither is the "real" one and the other a substitute. But they behave very differently once the piece leaves the store, and that difference is what should drive your choice.

Why October has two birthstones

Opal is the traditional October stone and has held that spot for centuries. Tourmaline was added as a modern alternative in 1952, when the American retail jewelers association — now Jewelers of America — revised the standardized birthstone list. The addition wasn't arbitrary. Opal is beautiful and genuinely delicate, and the trade wanted a harder-wearing option for customers who intended to put an October birthstone in a ring and never take it off.

So if you're buying for someone born in October, you aren't choosing between right and wrong. You're choosing between unique and durable.

Opal: the most individual stone in the case

No two opals are alike. Opal is hydrated silica — silicon dioxide with water held inside its structure — and that internal structure is what produces play-of-color, the flashes of green, blue, orange and red that shift as the stone moves. It's the reason people fall for opal in the first place, and it's the reason an opal you like is effectively irreplaceable. You can match a diamond. You can't really match an opal.

The trade-off is real. Opal ranks around 5 to 6.5 on the Mohs hardness scale, which is soft compared to most stones set in rings. And because opal holds water — sources commonly cite a range of roughly 3 to 21 percent — it reacts to its environment in ways harder gems don't. Extreme dryness, prolonged heat or a sudden temperature change can cause an opal to craze: a network of fine surface cracks that can't be polished out.

In practice, in Indiana, that means an opal ring doesn't belong in dishwater, doesn't belong on your hand while you're de-icing a windshield, and shouldn't be left on a sunny windowsill all summer.

Tourmaline: the widest color range of any gem

Tourmaline's claim to fame is color. It occurs in a broader color range than almost any other gemstone — pink, red, green, blue, and multicolored crystals including "watermelon" tourmaline, which shows pink at the center and green at the rim in a single stone. Pink tourmaline is the variety most associated with the October birthstone, but you are not limited to it.

Crucially for a gift someone will actually wear, tourmaline sits at 7 to 7.5 on the Mohs scale and contains no water. That makes it substantially better suited to a ring worn every day, and far less fussy about heat and temperature swings than opal.

Opal vs. tourmaline at a glance

A simple rule we use on the sales floor: if it's going on a hand, lean tourmaline. If it's going around a neck or in an ear, opal is a wonderful choice — the stone is far better protected there, and you get a piece nobody else on earth has.

How to care for an opal (this part matters)

Opal is the birthstone we most often see brought in damaged, and almost always for avoidable reasons. Keep these straight and an opal will last generations:

• Never use an ultrasonic or steam cleaner. The heat and vibration can fracture the stone outright. This is the single most common way opals get ruined at home.
• Clean it with a soft cloth dampened with lukewarm water and a drop of mild dish soap, then dry it right away. Not hot water — thermal shock cracks opals.
• If it's a doublet or triplet — a thin opal slice bonded to a backing, sometimes with a clear cap — don't soak it at all. Water works its way between the layers and separates them.
• Store it away from heat and direct sun, and not in an airtight bank-vault-dry environment for years on end.
• Put it on last, take it off first. Perfume, hairspray, lotion and cleaning products all belong on your skin before the opal goes on.

If an opal has gone cloudy, chipped, or worked loose in its setting, don't leave it in the piece hoping it holds. A loose stone is a lost stone. We check and tighten settings in-house at Greenwood Park Mall — the same approach we describe in our guide to what to do when a stone falls out of a ring.

Choosing an October birthstone gift

One more piece of timing advice: October birthdays land right as holiday shopping begins. If you want a custom piece — an opal reset into a new pendant, a tourmaline dropped into a redesigned setting — start that conversation in October rather than late November. Custom work takes time, and the bench gets busy.

October birthstone jewelry in Greenwood

At Forever Jewelry in Greenwood Park Mall, we carry and can source both opal and tourmaline, we'll tell you honestly which one suits the piece you have in mind, and we can reset or repair an existing opal in-house. We've served Greenwood since 2006, and we offer flexible financing options — ask us in store or browse at www.forever.jewelry.

Frequently asked questions

Celebrate an October birthday

Come see opal and tourmaline side by side at Greenwood Park Mall — the difference is much clearer in person than on a screen.