Opal Myths, Mysteries and Must-Knows: The Ultimate Guide to Opal Jewellery
By Charlotte McDonnell, Founder, Once Loved by Lottie
Few gemstones inspire as much curiosity as the opal. Its flashes of colour seem to shift and glow with every turn of the hand, which is exactly why opals have been treasured for centuries and why they feature in lots of antique and vintage jewellery. They also come with plenty of questions, and a few myths. Here are the ones we hear most often, with some straightforward answers!
What is an opal?
Opal is a gemstone formed from silica and water, laid down over millions of years in tiny spaces within the earth. Unlike most gemstones, it has no crystal structure. Instead, microscopic spheres of silica stack together and bend light into the rainbow flashes known as ‘play of colour’. Stones that show this effect are called precious opal, while those without it are known as common opal. Because every stone's pattern forms differently, no two opals are exactly the same.
Can you wear an opal every day?
You can, but it helps to choose the piece wisely. Opal sits at around 5.5 to 6.5 on the Mohs hardness scale, which is softer than diamond at 10, or sapphire and ruby at 9. This means it can scratch or chip if knocked. Everyday dust contains tiny particles of quartz that are harder than opal, so a ring worn constantly will gradually show wear. Earrings and pendants sit away from the knocks of daily life, which makes them the easiest opal pieces to wear often. If you love an opal ring, wear it for your meals out and special occasions and definitely remove for washing up, gardening or the gym – anything wet, messy or knocky! A protective setting, such as a bezel or deep claws, adds extra reassurance.
Can opal rings get wet?
A little water will not harm a good solid opal, and an occasional splash or hand-wash is fine. Opal naturally contains water, so it is not a stone that dissolves or fades when damp. The real risks are prolonged soaking, hot water and sudden temperature changes, which can stress the stone over time. Opals that are made up of layers, known as doublets and triplets, are much more vulnerable, as water can seep between the layers and cause cloudiness or even separation. Some porous opals, such as certain Ethiopian stones, can also absorb water and look temporarily different. As a rule, take your opal ring off for swimming, showers, baths and hot tubs, and absolutely avoid chlorine, soaps and household cleaning products.
How can you tell the difference between a real opal and a fake?
Start by looking closely. Natural opal has an irregular, organic pattern, and the colour flashes change as you tilt the stone. Imitations often look too perfect, with uniform dots or a repeating, scale-like pattern, and the colours can seem flat or overly even. Check the side of the stone as well: doublets and triplets (real opal fused to a backing or topped with a clear cap) often show a visible join line, a dark backing layer or a glassy dome. These are genuine opal but are valued very differently from a solid stone. Also be wary of a price that seems too good to be true, and note that some opals are treated or enhanced, which should always be disclosed. The most reliable route is to buy from a seller who is open and honest about the type of opal, its origin and any treatments, and to ask a qualified gemmologist or jeweller if you are unsure. Avoid DIY tests that involve heat or chemicals, as these can damage a real stone.
What is the difference between solid opal, doublets and triplets?
A solid opal is cut from a single piece of natural opal and shows its colour all the way through. A doublet is a thin slice of opal attached to a dark backing, usually to boost the colour and make thin material usable. A triplet adds a clear dome of quartz or glass on top for protection. Solid opals are the most valuable and the most durable over time, while doublets and triplets are more affordable but need gentler care, especially around water and cleaning.
What makes an opal more expensive?
Several things work together. Body tone matters most: darker opals, with black being the rarest, show colour more dramatically and command higher prices than white or crystal opals. Then the play of colour itself, where bright, intense flashes covering the whole stone are prized, and red is generally the rarest and most valuable colour. An opal showing the full colour spectrum are usually the most desirable. Pattern also counts, with striking, defined patterns being rarer than plain flashes. Beyond that, size, thickness, clean cutting, origin and any treatments all play a part, and a solid opal will always be worth more than a doublet or triplet of similar appearance. In vintage and antique pieces, age, craftsmanship, hallmarks and the quality of the setting add further value.
What are the different types of opal?
The main types you will come across are:
§ White opal - a pale, milky body with soft flashes of colour
§ Black opal - a dark body that makes colours appear to glow, and the most sought-after
§ Crystal opal - translucent and glassy
§ Boulder opal - thin seams of opal on ironstone, usually from Queensland
§ Fire opal - warm orange or red, often without play of colour
§ Ethiopian opal - known for vivid colour, though often more porous
Australia produces the vast majority of the world's precious opal, but stones from other countries, including Ethiopia and Mexico, are increasingly popular.
Are opals unlucky?
No, and the superstition is mainly a literary accident. For centuries opal was considered a stone of good fortune, hope and even protection. The reputation for bad luck is usually traced to Sir Walter Scott's 1829 novel Anne of Geierstein, in which an enchanted opal brings misfortune to its owner, and the myth stuck. It was later said to be unlucky for anyone not born in October, though the Victorians clearly did not mind, as Queen Victoria famously loved opals and gave them to her children. Today most people see the opal as a symbol of creativity, hope and individuality, and antique opal jewellery is as sought after as ever.
Is opal October's birthstone?
Yes. Opal is one of the two birthstones for October, alongside tourmaline, which gives October babies a choice between the ethereal shimmer of opal and the wide colour range of tourmaline. Opal is also often linked with 14th wedding anniversaries. It makes a thoughtful and unusual birthday gift, particularly in a vintage setting with a story of its own.
What does an opal symbolise?
Opal has long been associated with hope, creativity, faithfulness and inspiration, and because it contains every colour of the rainbow, it was once thought to carry the powers of all gemstones. Each of those meanings is a matter of tradition rather than science, but they add to the romance of giving or wearing an opal.
Is opal a good choice for an engagement ring?
Opal can make a beautiful and very personal engagement ring, and many antique opal engagement rings have survived for over a century. It is simply a softer stone, so it needs a little more care than a diamond. A protective setting, a considered lifestyle choice and a commitment to taking the ring off for heavy activities will help it last. Many people choose to pair opal with diamonds, which both frames the stone and adds sparkle, or reserve the opal ring for special occasions and wear a sturdier band day to day.
How do you clean opal jewellery?
Keep it simple. Wipe the stone gently with a soft, damp cloth and dry it straight away, using a soft brush for any dirt around the setting. Avoid ultrasonic cleaners, steam cleaners, harsh chemicals and jewellery dips, all of which can damage opal, particularly doublets and triplets. It’s particularly important to avoid heat and cold which can ‘shock’ the stone and cause it to crack. For anything stubborn, or for antique pieces, it is safest to take your jewellery to a jeweller who is experienced with opal such as Nicholas Wylde in Bristol and Bath, UK.
How should you store opal jewellery?
Store each piece separately in a soft pouch or lined jewellery box so that harder gemstones, such as diamonds, cannot scratch it. Avoid very dry or very hot places, such as next to a radiator or in direct sunlight for long periods, as extreme dryness and heat can stress the stone. A cool, stable room is ideal.
Can opals crack or dry out?
They can, though it is uncommon with well-sourced stones. Because opal contains water, sudden temperature changes or very dry conditions can occasionally cause fine surface cracks, a condition known as crazing. Buying from a reputable seller, avoiding extreme heat and wearing your opal regularly (skin contact helps keep it comfortable) all help to protect it. Antique opals that have lasted a century or more have already proved they are stable.
Can you resize an opal ring?
Often yes, but it should be done carefully by a jeweller who understands opal. Heat from soldering can damage the stone, so the opal is sometimes removed before work begins, which carries a small risk. This is worth bearing in mind if you are buying a ring that is not quite your size. It is always best to ask about resizing before you buy. At Once Loved by Lottie, I will advise on resizing and carry out any work via my preferred workshop where they have decades of experience. They will advise against resizing where they feel the risk to the opal is too high but resizing two sizes either way is usually absolutely fine.
Why choose antique and vintage opal jewellery?
Opal was hugely popular in Victorian and Edwardian jewellery, and surviving pieces often show a level of craftsmanship that is hard to find today. Choosing a vintage opal also means choosing a piece that has already stood the test of time, and buying pre-loved is a more sustainable choice. At Once Loved by Lottie, every piece is hallmarked, carefully chosen and described honestly, so you know exactly what you are buying.
Browse our collection of antique and vintage gemstone jewellery at oncelovedbylottie.co.uk.