| Australia
is the world's greatest producer of precious
opal. Over 90 per cent of the world's commercial
opal comes from the desolate outback. All
of the significant opal deposits in Australia
are located within the Great Artesian Basin
or close to it. The places where opal has
been mined over the past 100 years are located
here. The most important deposits are found
in New South Wales, South Australia and Queensland.
Today,
the mining is carried out at the following
main areas and each produce solid opal
with specific characteristics and colour
patterns.
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Lightning
Ridge, NSW
This is a town famous for its rich,
rare and glorious black opal. Black
opal derives its name from the colour
of the 'nobbies' or pieces of rough
opal in which the gems are usually found.
Lightning Ridge is located 770 kilometres
northwest of Sydney in an area that
also produces wheat, sheep, cattle and
oilseeds.
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Black
opal was first discovered at Lighting
Ridge in the late 1880s however, its
commercial value was not at first recognised
by buyers. Mining actually commenced
in the early 1900s when some opal nobbies
were found and trial shafts erected.
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Opal
occurs at Lightning Ridge either as
'nobbies', or in seams and thin layers
within vertical or horizontal joint
plains, in a soft greyish claystone
that hardens and whitens on drying.
This claystone is commonly referred
to as 'opal dirt'. The opal dirt levels
occur between 6 and 18 metres from the
surface, but have been known to go as
deep as 30 metres.
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The
fields also yield opalised shells, wood,
and reptilian bones of the Cretaceous
age.
Some
of the traditional fields around Lightning
Ridge include the Three Mile and Thorleys
Six Mile however, most opal is now being
found in newer areas away from the township.

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White
Cliffs, NSW
White Cliffs is Australia's oldest commercial
opal field. It is located 295 kilometres
northeast of Broken Hill. Opal was first
mined at White Cliffs about 1889, and
the population peaked at 5,000 in its
heyday despite the water shortages.
Digging was very easy, and the light
opal was very clean and found a ready
market in Europe. The light crystal
opal found at White Cliffs quickly became
famous on the world markets.
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For
30 years the White Cliff opal fields
produced the first commercially accepted
opal on the world markets, far surpassing
the quality of the Hungarian opal. Opal
displaying such vivid colours had never
been seen before. The colourful seam
opal was very easy to value and it did
not shatter like other opal when cut
and polished.
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From
1903 to 1914, the richer areas of the
opal field became exhausted thus resulting
in a decline in production. White Cliffs
suffered and never recovered from the
effects of World War I and the loss
of the European markets. Today, White
Cliffs is a unique town and very popular
with the tourists, fossickers and miners.
The modern age has brought electricity
to the town and water is readily available.
Some of the townspeople still prefer
to live underground where it is cool
in summer and warm in winter.
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Although
there is not much new ground left on
the old opal field to sink a shaft,
one can fossick among the old diggings.
There are those who say that more opal
than the amount mined remains in the
ground ready for discovery: a new lucky
strike will one day turn White Cliffs
into a boom town again!

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Central
Queensland
The history of opal in Queensland dates
back to the early 1870s, but it wasn't
until 1889 when the gem was successfully
marketed that the industry became established.
The discovery of opal was reported in
many areas however, the real development
of Queensland's vast opal deposits began
in 1873 with the discovery of fine quality
opal north of Thargomindah. Within two
years there had been many exciting finds
throughout south western Queensland
however, during those early years production
was low because there was no ready market
for the gem. It took the tireless efforts
and sheer determination of a young entrepreneur
named Tully Wollaston to convince world
gem merchants to accept Queensland opal
that the industry was finally established.
Today,
the Queensland opal belt covers an extensive
area in the southwest of the state that
is around 1000 kilometres long by 300
kilometres wide. There are local areas
throughout the region where opal mines
are concentrated, such as Yowah, Quilpie,
Eromanga and Jundah.

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Coober
Pedy, SA
Coober Pedy was discovered in 1915.
This is where the 'white' or 'milky'
opals (generally known as 'light opal')
are mined. Until recently, Coober Pedy
was the main producer of precious opal,
which is why it is predominantly seen
in stores overseas, particularly in
the USA.
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Today,
the opal fields encompass an area of
approximately 45 kilometres. The opal
level is formed of soft pinkish clay
mixed with soft bleached sandstone.
The
name Coober Pedy is derived from the
Aboriginal word kupa piti, which when
loosely translated means "White Man
in a Hole". An isolated and rugged location,
Coober Pedy is blessed with freezing
nights, days where the average temperature
seldom drops below 40¡C, and bush flies
by the million. Coober Pedy is too hot
for life to exist comfortably on the
surface, so homes were made in underground
burrows, which gave the field its name.
Virtual palaces have been built underground,
providing a constant temperature of
between 21¡C and 26¡C.

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Mintabie,
SA
It is believed that Aborigines were
the first to sell black opal from Mintabie
at Coober Pedy just after the First
World War. They were able to keep their
secret for some time until eager miners
discovered the opal field in the early
1930s. As a result of the remoteness
of the area and the lack of water, Mintabie
was worked only on a very small scale
until 1976, when heavy earth-moving
machinery moved in. The opal is sandwiched
between hard layers of sandstone, and
the rock layers below the ground are
drilled or blasted through with explosives
to enable the bulldozers to get to the
opal bearing ground.
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This
area is now producing very attractive
light and semi-black opal. Mintabie
black opal usually occurs on a mid-grey
background therefore, although respected
in the black opal markets, commands
a lower price than the darker Lightning
Ridge black opal.
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Andamooka, SA
Andamooka is found southwest of Coober
Pedy in harsh desert country. Discovered
in 1930, Andamooka is one of Australia's
most famous opal fields, having produced
some of the most beautiful pieces of
opal.
Andamooka is derived from an Aboriginal
name, meaning 'Large Waterhole'. It
is located 600 kilometres north of Adelaide,
and is the only Australian town where
none of the streets is named.
The
opal fields in and around Andamooka
produce top gem, crystal, light opal
and some dark opal.

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