All of Nature's splendour seems to be reflected in the manifold
opulence of fine Opals: fire and lightnings, all the colours of the
rainbow and the soft shine of far seas. Australia is the classical
country of origin. Almost ninety-five per cent of all fine opals
come from the dry and remote outback deserts.
Numerous legends and tales surround this colourful gemstone, which
can be traced back in its origins to a time long before our memory,
to the ancient dream time of the Australian aborigines. It is
reported in their legends that the creator came down to Earth on a
rainbow, in order to bring the message of peace to all the humans.
And at the very spot, where his foot touched the ground, the stones
became alive and started sparkling in all the colours of the rainbow.
That was the birth of the Opals.
The group of fine Opals includes quite a number of wonderful
gemstones, which share one characteristic: they shine and sparkle in
a continually changing play of colours full of fantasy, which
experts describe as “opalising”. Depending on the kind, place of
occurrence, and colour of the main body, we differentiate Dark or
Black Opal, White or Light Opal, Milk or Crystal Opal, Boulder Opal,
Opal Matrix, Yowah Nuts from Queensland – the so-called “picture
stones“, and also Mexican and Fire Opal . Opal variations are
practically unlimited. They all show in their own special way that
unique play of colours – except for Fire Opal, which due to its
transparency, however, is nevertheless also considered a Fine Opal
specimen. If Opals are lacking the typical play of colours, they are
simply named “Common Opal”.
Upala, opallios or Opalus – fascination created by tiny spheres
The name Opal was probably derived from Sanskrit “upala“, meaning
”valuable stone“. This was probably the root for the Greek term “opallios”,
which translates as “colour change”. In the days of Roman antiquity
there existed a so-called “opalus”, or a “stone from several
elements”. So the ancient Romans may already have had an inkling why
the Opals show such a striking play of colours. But we will come to
this later …
Pliny, the famous Roman author, called Opal a gemstone which
combines the best possible characteristics of the most beautiful of
gemstones: the fine sparkle of Almandine, the shining purple of
Amethyst, the golden yellow of Topaz, and the deep blue of Sapphire,
”so that all colours shine and sparkle together in a beautiful
Up to the first half of the 19th century, Opals were relatively
rare. But then their career boomed suddenly and made them one of the
most popular gemstones, and the start of this development brought
them to the gemstone cutters of the gemstone centre of
Idar-Oberstein. In the era of Art Deco the Opals experienced their
flourishing, with contemporary gemstone artists preferring them to
all other stones because of their subdued charm, which in turn was
excellently suited to be combined with enamel, another very popular
material of those days.
Opal's colour play emanates a very special attraction and
fascination. But what causes this phenomenon? This question was
impossible to answer for a very long time. Only when in the 1960s a
team of Australian scientists analysed Opals with an electron
microscope, it was discovered that small spheres from silica gel
caused interference and refraction manifestations, which are
responsible for the fantastic play of colours. The spheres, which
are arranged in more or less compact structures, succeed in
dissecting the light on its passage through the gemstone and turning
it into all the colours of the rainbow, always new and always
Australia, classical Opal country
Australia is the classical Opal country and today is the worldwide
most important supplier of Fine Opals. Almost 95 per cent of all
Opals come from Australian mines. The remaining five per cent are
mined in Mexico, and in Brazil's north, also in the US states of
Idaho and Nevada, but recently the stones have also been found in
Ethiopia and in the West African country of Mali.
The history of Australian Opal began actually millions of years ago,
when parts of Australia were covered by a vast inland sea, and stone
sediment was deposited along its shoreline. When the water masses
flooded back, they flushed water containing silica into the
resulting cavities and niches in the sedimentary rocks, and also the
remains of plants and animals were deposited there. Slowly the
silica stone transformed into Opal, for basically Opals are simply a
combination of silica and water. Or, to be more precise: Opals are a
gel from silica, with varying percentages of water.
In 1849 the first Opal blocks were accidentally found on an
Australian cattle station called Tarravilla . the first Opal
prospectors started in 1890 at White Cliff mining the Opal rocks.
And even today the eyes of Opal lovers light up when somebody
mentions places like White Cliffs, Lightning Ridge, Andamooka or
Coober Peddy: for these are the legendary sites of the Australian
Opal fields. The most famous one is probably Lightning Ridge, the
place where mainly the coveted Black Opal is found. Andamooka, where
Crystal Opal and Light Opal are brought to the light of day, cam
boast to be the place where the probably largest Opal was found,
with a weight of 6 ,843 kilograms, the “Andamooka Desert Flame”.
Coober Peddy, by the way, is a word from Aborigine language meaning
„white man in a hole“. This clearly describes how Opal was in fact
mined: many Opal prospectors made their home in deep holes or caves
in the ground, to protect themselves from the burning heat of
daytime and from the icy winds of night time. Usually they worked
only with tolls such as pick and shovel. Buckets full of soil,
hopefully containing Opal rocks, were pulled up out of the depths of
5 to 40 m deep shafts by hand, for this is the depth of the Opal
containing crevices and cavities, which are also mined nowadays.
Being an Opal prospector is still not an easy job, although today of
course there are some technical means available, such as trucks or
conveyor belts. And still the hope to make the find of a lifetime
which will let you live happily ever after attracts many men and
women to come to the hot and dusty Australian outback.
About cabochons, doublets and triplets
In order to best bring out the play of colour in a Fine Opal, the
stones are cut and polished to round or oval cabochons, or any other
softly domed shape , depending on the raw material. Only the best
qualities of Fire Opal, however, are suited to faceting. The Opal
cutter will first of all carefully remove any impurities using a
diamond cutting wheel, before working out the rough basic shape. The
comes the fine cutting, the finishing with sandpaper and then the
final polishing with a wet leather wheel.
Opal is often found as flat lenses, or thin layers, bigger pieces
are rather rare. If you leave a thin but supporting layer of the
harder mother rock, you will receive a pre-stage of the
Opal-doublets which are frequently used today for mass produced
jewellery. These are gemstone combinations consisting of a surface
from millimetre-thin Opal plates, which have been mounted on Onyx,
Obsidian, artificial black glass, or Potch-Opal. Triplets have been
developed from this design, here the Opal layer receives an
additional cover from Rock Crystal, Plastic, Hard Glass or Lead
Glass for protection.
Opal love to be worn on the skin
Due to the differing percentage of water, Opals may easily become
brittle. They always contain water – usually between 2 and 6 per
cent, but sometimes even more. Thus if stored too dry or exposed to
heat over a longer period of time, Opals will show fissures and the
play of colour will become paler. Therefore, Opal jewellery should
be worn as often as possible, for then the gemstone will receive the
needed humidity from the air and from the skin of its wearer.
Opals are not very hard: they only achieve 5.5 to 6 on the Mohs'
scale. Therefore they appreciate a protective setting. In earlier
days Opal's sensitive surface was often oiled, but today also
sealing them with colourless artificial resin has become quite
From Harlequin to Peacock: Opal experts lingo
When Opal experts talk about “harlequin”, “church windows” or
“needle fire”, do not be surprised. They are probably discussing
Opals. The play of colour in this stone is described with many
imaginative terms for various structures and phenomena, like, for
example, “flame opal”, “lightning and peacock opal”, or the above
named “harlequin” and “church window”.
Opal's value is not only determined by the body colour, transparency
and factors based on place of occurrence. (Body colour refers to the
basic colour of the gemstone, which can be black, dark or light and
coloured). It is also important if the stone is transparent,
translucent or opaque. And the opalizing effect may also influence
Black Opal or Opal with a dark grey body shows the most brilliant
play of colours imaginable. Crystal opal, which comes immediately
after Black Opal in the hit list, should be more transparent with a
deep play of colours. White or milky Opals show more diffuse colours
and are the least expensive Opals. The occurrence-specific
characteristics include, for instance, denominations such as “Black
Opal from Lightning Ridge” (we are talking absolute top luxury here)
or “Mexican Fire Opal”.
The most important criterion for determining the price of an Opal,
however, is the play of colour, the colours as such and their
pattern. If the colour red appears when looking through the stone,
all the other colours will appear also. For evaluating Opals the
thickness of the Opal layer is considered, the beauty of the
patterning, the cut, weight and finish. Finally the total impression
will be decisive, and of course offer and demand will determine ho
much you will have to pay for “your” Opal. If you are interested in
a really valuable specimen, get an Opal expert to advise you,
because it takes a real expert to know about the many criteria which
determine the price.
Opals and emotions
For ages people have been believing in the healing power of Opal. It
is reported to be able to solve depressions and to help its wearer
find the true and real love. Opals are supposed to further enhance
the positive characteristics for people born under the zodiac sign
of Cancer. Black Opal is recommended to those born under Scorpio,
and Boulder Opal is the lucky stone for Aries.
The fantastic colour play of Opal reflects changing emotions and
moods of people. Fire and water, the sparkling images of Boulder
Opal, the vivid light flashes of Black Opal or the soft shine of
Milk Opal – striking contrasts characterise the colourful world of
this fascinating gemstone. Maybe this is the reason why it depends
on our daily mood which Opal we prefer.