Opal and Fire Opal
Play-of-colour like nothing else, and the care it genuinely requires
About Opal and Fire Opal
Opal does something no other gemstone does. Its play-of-colour flashes green, blue, red and orange as it moves, produced by microscopic silica spheres diffracting light rather than by any pigment. No two opals are alike, and photographs never quite capture them.
Fire opal is its translucent orange-red cousin, which glows rather than flashes and is often faceted where play-of-colour opal is cut as a cabochon.
Both are soft, at Mohs 5.5 to 6.5, and both contain water. That combination makes opal the most care-dependent stone we sell, and we would rather say so plainly than let someone discover it later.
The Palette
Swatches are indicative. We will always show you the actual stone in more than one light.
Why Opal and Fire Opal Works
Nothing else looks like it
Play-of-colour is a genuinely unique optical effect. If it is what you want, no substitute exists.
Every stone is unique
Opals cannot be matched or replaced like for like, which makes each piece genuinely one of a kind.
The October birthstone
Alongside tourmaline, which is the hardier option for anyone who wants October colour in a ring worn daily.
Extraordinary value at the lower end
A characterful white opal costs very little. Fine black opal, at the other extreme, reaches serious prices.
What to Watch
- Soft, at Mohs 5.5 to 6.5It will scratch, and it needs a protective setting.
- Opal contains waterExtreme dryness or heat can craze it. Never leave it in strong sun or a hot car.
- Hydrophane opal absorbs liquidSome Ethiopian opals temporarily lose play-of-colour when wet, and take days to recover.
- Never use an ultrasonic cleanerWarm soapy water and a soft cloth only.
The Practical Facts
- Hardness
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5.5 to 6.5 on the Mohs scale
1 · TalcSofter than sapphire, harder than pearl10 · Diamond - Toughness
-
Poor to fair; crazing is a real risk
- Suited to
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Pendants, earrings, occasional rings in protective settings
- Common treatment
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Stabilising possible; doublets and triplets exist
- Price range
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£ to ££££, depending enormously on type
- Birthstone
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October
Hardness describes scratch resistance, not toughness. The two are different and both matter.
Setting It Well
Bezel settings and low profiles only. A cabochon opal in a rubover setting with the edges protected is the sensible construction. We would not recommend an opal for an engagement ring worn every day, and if someone wants one anyway we will make it while being clear about what it will need.
Opal and Fire Opal Questions We Are Asked Most
Can I have an opal engagement ring?
You can, and we make them, but you should go in with clear expectations. At Mohs 5.5 to 6.5 an opal will scratch and can craze. It needs a protective setting, removal for anything physical, and gentle cleaning. For a ring worn daily on an active hand, we would honestly suggest something else.
What is crazing?
A network of fine cracks that can develop when an opal dries out or is subjected to sudden temperature change. It is not repairable. Keeping opal away from heat, direct sun and dry environments is the best prevention.
What is a doublet or triplet?
Assembled stones: a thin slice of opal backed with dark material, and in a triplet also capped with quartz. They make the colour more dramatic and the stone cheaper, but they are not solid opal and must be disclosed. They should never be immersed in water.
Why do some opals go clear when wet?
Hydrophane opal, mainly from Ethiopia, is porous and absorbs water, which temporarily kills the play-of-colour. It usually returns over hours or days as the stone dries. It is a known characteristic rather than a fault, but it is a reason to keep such stones out of water.
The Diamond and Gemstone Guide
Every gemstone stone by stone, plus durability, treatments, ethical sourcing and grading reports.
Round
Pear
Princess
Emerald
Oval
Asscher
Cushion
Marquise
Radiant
Heart
