Opal: The Birthstone That Contains a Thousand Colours

Opal has been October's birthstone for centuries, and it earned that place honestly. No other gemstone behaves quite like it. Cut into a diamond or a sapphire, and the colour stays put. Turn an opal in the light, and it shifts. Reds fold into greens, blues catch fire, gold flickers across the surface like something alive underneath.

That effect has a name: play-of-colour. It happens because opal is built differently to most gemstones. Instead of a crystal structure, opal is made of tiny silica spheres, stacked in a pattern so fine that light bends and splits as it passes through. The size and arrangement of those spheres determine which colours show up and how they move. No two opals are arranged the same way, which is why no two ever look alike.

Australia produces most of the world's opal, and a large share of that comes from a handful of outback mining towns — Coober Pedy, Lightning Ridge, Andamooka. Australian opal tends to have a darker or lighter body tone with strong, saturated colour flashes, which is part of why it's so prized internationally. For a jewellery studio based in Perth, that connection feels close to home. Some of the most striking opals we've worked with have come straight from Australian ground.

Opal isn't a single look. Black opal has a dark background that makes its colours pop with real intensity, and it's the rarest and most valuable type. White or light opal has a paler base, so the colours sit softer and more pastel. Boulder opal forms attached to a thin layer of ironstone, which gives it a natural depth and a rougher, more organic edge. Each type suits a different kind of piece and a different kind of person, which makes opal a genuinely flexible stone to design around, not just a single fixed look.

Opal has long been associated with hope, creativity, and emotional depth — fitting, given how much it seems to hold within itself. Victorian-era folklore linked opal to loyalty and to protecting the wearer, and it's stayed a stone people give and wear with meaning attached, not just decoration. If you're designing a piece for someone born in October, that layered symbolism gives you something to build the story around.

Opal is softer than diamonds or sapphires, sitting around 5.5 to 6 on the Mohs hardness scale. That doesn't rule it out for daily wear, but it does mean the setting matters. A bezel setting, where metal wraps around the edge of the stone, gives opal real protection from knocks. Earrings and pendants take opal beautifully with fewer wear concerns than a ring worn every day. When we design with opal, we talk through how the piece will actually be worn and build the setting around that, so the stone lasts as long as the person wearing it.

October also carries a second birthstone: tourmaline. It was added to the official birthstone list in 1912, largely because it offered a hardier, more affordable option alongside opal. Tourmaline comes in an enormous range of colours too — pink, green, blue, and watermelon tourmaline, which shifts from pink to green within a single stone. It's a strong choice for anyone who wants their birthstone in a ring worn every single day without a second thought. Opal remains the stone most people picture when they think of October, but tourmaline holds its own place in the story.

Both Opal and Tourmaline reward a personal approach, though for different reasons. Because every opal carries its own pattern of colour, a piece built around it often starts with the stone itself, and the setting, metal, and surrounding stones are chosen to complement what's already happening inside it. Tourmaline gives you more room to work the other way around — since it comes in such a wide range of colours, it can be chosen to match an existing design, a birthstone piece for someone else in the family, or a colour palette you already have in mind.Whichever stone you're drawn to, we'd love to talk through it with you and build a piece that fits how it'll actually be worn, whether that's an opal pendant chosen for its one-of-a-kind colour play or a tourmaline ring designed for daily wear.