'You’ll never find another one like this!' How many times have you heard that old chestnut?
Well, if that chestnut is applied to opals, it is usually true.
Of course, all gemstones are different even if part of the same family, but with opals, finding a matched pair is almost impossible.
If you are lucky enough to own a beautiful opal with a good play of colour you will see something different every time you look at it.
Turn it a different way or change the light source and different flashes of colour will come into play.
Opals are the October birthstone and given to celebrate a 14th wedding anniversary but the origin of their name is as varied as the play of colours in the gemstones themselves.
Some say it evolved from the Greek ‘opallios’ meaning ‘to see a change in colour’.
The Romans called it ‘opalus’ meaning ‘precious stone’ in Latin and many attribute the name to the Sanskrit ‘upala’ also meaning ‘precious stone’.
Whatever the true derivation of its name, throughout history opal has excited very different responses, some good some bad, both as to its origin and properties.
To some it is lucky and highly prized and to others it is evil and the bearer of bad luck.
The Bedouins thought it held lightning and fell from the sky during thunderstorms.
Ancient Greeks thought opals bestowed the gift of prophesy and protection from disease.
Europeans long maintained opal to be a symbol of purity, hope and truth.
Hundreds of years ago, opal was believed, not surprisingly, to embody the virtues and powers of all coloured stones.
The Romans highly prized opal considering it second only to emerald.
They believed that opals brought good luck and carried them as talismans.
Caesars gave opals to their wives and Mark Antony banished Senator Nonius for refusing to sell his almond shaped opal to him.
No prizes for guessing who Mark Antony wanted to give that opal to?!
The early Greeks believed opals gave their wearers the power of prophecy and in other cultures it was a symbol of hope innocence and purity.
Napoleon presented Josephine with the ‘Burning of Troy’ – an opal with brilliant red flashes. This opal is apparently long lost but wouldn’t you like to be the one who rediscovered it!
Queen Victoria loved opals. She wore them and often gave them as gifts.
Her love of the same increased their popularity and she was able to feed that love due to the discovery of fine opals in Australia in 1872.
However opal was also associated with the Evil Eye by the Elizabethans who called it ‘ophals’ – a derivative of 'opthalmos' which referred to the human eye.
It became associated with famine pestilence and plaque due in part to the rumours put about that an opal lost its brilliance immediately its wearer died of the Black Death.
The tragic sequence of events that befell Alfonso XII of Spain in the 19th century certainly didn't help.
He gave an opal ring, a gift from a jilted prospective wife, to his new wife who died within 2 months.
The ring was then given to his grandmother who died shortly thereafter.
It was then given to his sister who also died.
His sister-in-law became the next owner - yes you’ve guessed it – she quickly died.
Alfonso then decided to wear it and – yes – he died!
This was of course attributed to the opal rather than the various diseases and illnesses that regularly and indiscriminately took lives at that time.
Sir Walter Scott’s novel Anne of Geierstein didn't help opals' reputation as it appeared to link opal to the death and misfortune of its heroine. In fact the novel had a drastic effect on the opal market for several decades.
When Australian opals began to appear in the market in the late 19th century, diamond traders played on opals' reputation as unlucky to protect diamond sales.
Many jewellers and setters do not like working with opals as there have been mishaps when setting them.
Think of Louis XI’s goldsmith who had his hands cut off for breaking the King’s opal when setting it!
Opal is an amorphous hydro-silicate composed of silicon and oxygen with a percentage of water within its structure.
Simply put, water percolates through the earth and rock carrying dissolved silica. As most of the water evaporated it left solid deposits of silica in the cracks and natural voids between the layers of underground sedimentary rock.
Those silica deposits formed opal.
This process repeated over many years to form opal.
An opal is not coloured in the sense of coloured gemstones.
Rather opals have a play of colour.
This is attributed to diffraction - the bending of light as it passes around the edge of an object.
Remember that opal is formed of tiny silica spheres. These spheres vary in size and number and are stacked in a grid-like pattern.
When light enters the opal, it travels between the spheres but to do so it has to bend and the bending splits the light and produces the spectrum of rainbow colours resulting in the play of colour.
The play of colour depends on the size of the spheres.
Smaller ones bring out the violets, blues & greens whilst larger ones brings out the reds, oranges and yellow.
Opals having a play of colour are known as 'precious opal'.
Some opal, referred to as common opal or 'potch', does not have a play of colour.
This is because the spheres are randomly sized and arranged.
Finding potch or common opal in the ground is often seen as a positive sign - if potch is present, there is a chance that precious opal may also be present, but it is not a guarantee of precious opal.
And just to complicate matters further, an opal will have a background colour ranging from clear to white to blue to black caused by tiny impurities suspended within the spheres.
Black opal is a generic term given to any opal which has a dark body colour when viewed from above.
The more play of colour particularly reds and oranges against the dark body colour the more desirable it is.
The majority of black opal is found in Lightning Ridge Australia.
Light Opal is usually called “white", but this should only refer to opals that have a milky or white body colour.
The majority of light opal is found in South Australia.
Boulder opal is often just a thin vein of opal on an ironstone back or matrix.
Sometimes if the vein is very thin the ironstone will be visible.
They are usually cut in irregular shapes with the ironstone boulder left on the back.
Boulder opals are mainly found in Western Australia.
Boulder opal matrix has distinctive patterns of opal veins within the ironstone.
Sometimes the opal forms as a central kernel or nut within a small boulder.
These are known as ‘nuts’ and are found at Yowah & Koroit Australia.
Fire opals are predominantly red orange or yellow.
The description is sometimes wrongy used to refer to light or white opals that have a strong play of colour particulary with orange or red.
Fire opals are often known as Mexican opal, where most of it is found.
A triplet opal is effectively a sandwich!
A thin slice of opal usually with a good play of colour is glued between a black backing and a crystal top.
A doublet opal is an open sandwich i.e. – a slice of opal again with a good play of colour glued to a black backing.
It does not have the top crystal layer that the triplet has and the slice of opal will usually be thicker.
Opals are often referred to as a soft stone having a hardness on the Moh’s scale of 5 to 6.5.
Diamond is the hardest stone registering 10 on the Moh’s scale, with ruby & sapphire at 9 and emerald at 7.5 to 8.
With many years of wear (less if you are hard on your jewellery) most gemstones will scratch and rub making the surface looking dull.
They can however be repolished by experienced lapidarists to restore their former glory.
Opals are no exception and are susceptible to scratching and chipping.
If you want to wear an opal in a ring, give some thought to setting it in a protective setting e.g. a rubover setting rather than claws.
Consider surrounding it with harder gemstones preferably diamonds, sapphires or rubies.
Don’t wear your opal ring whilst gardening or doing sports, in fact take it off if there is any chance that it could be scratched or broken by the activity that you are undertaking.
Although opals contain a percentage of water, they can dry and crack if subjected to very dry conditions or rapid changes in temperature.
So don’t leave your opal for long periods in bank vaults or safes which have little or no humidity and don’t put them into boiling or very hot water – another reason not to wear an opal ring whilst washing up.
Store your opal jewellery away from direct contact with other jewellery that could scratch it including gemstones that are harder.
Keep it its own cotton bag in your jewellery box .
Doublets and triplets should never be soaked in water or subjected to prolonged exposure to water: over time this will cause the glue holding the layers together to lift, water will then get in between the layers and create a grey or foggy appearance.
Brief or one-off exposure should not be a problem.
Ethiopian opal from Wollo known as Welo opal is hydrophane which means that it can absorb water like a sponge.
This can lead to temporary colour loss or change and to cracking so do not expose Welo opal to water.
We recommend that you remove all opal rings when washing your hands - if it’s a Welo it will not like the water and if it is not the hand soap/sanitiser may contain drying agents which other types of opal do not like.
Do not wear any opal jewellery when swimming – Welo triplet and doublet opals won’t like the water and other opals won’t like the chlorine or other chemicals in swimming pools.
Opal jewellery regardless of its type or origin should never be cleaned in an ultrasonic cleaner.
It should also be kept clear of hydrofluoric acid and caustic alkaline solutions so avoid bleaches, chemicals & cleaners and we also recommend that you avoid contact with perfume & hand sanitisers in fact anything that contains alcohol – so don’t clean it in gin!
The simplest way to clean an opal is by using a damp cloth but do not use a hair dryer to dry it!
If you are not sure whether your opal is solid, a triplet, a doublet or hydrophane, take it instead to an experienced jeweller, especially one who understands has opals, for cleaning.
The above ‘dos and don’ts’ may sound a bit scary but many of them apply to the care of lots of other gemstones so don’t be put off from wearing your opal jewellery.
The GIA suggests that you ‘consider your opal ring like silk: beautiful but requiring a bit more care than cotton’.
In the (altered) words of the song ‘Opal is a many splendored thing’.!
Magnificent, unique, fascinating, wondrous and becoming ever rarer.
Forget the old wives’ tales about bad luck, yes they need a little more care than some gemstones, but take that care and you will wear and enjoy your opals for many years.
Let’s give Pliny the Elder, to whom opal was the most valuable and prized gemstone of the Empire, the last word:
'For in them you shall see the living fire of the ruby, the glorious purple of the amethyst, the sea green of the emerald, all glittering together in an incredible mixture of light.'
Sources:
Oxford University Museum of National History
Opals down Under
Web Exhibits
Gem-A
GIA Education
Cody Opals
Variance
National Opal Collection
Opal Auctions
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