AUSTRALIAN OPALS
G'day folks,
Ever seen an opal? Keep reading. They are one of the greatest natural delights on earth. Visitors
to South Australia from 25 September will have the chance to go back in time
100 million years to a time when dinosaurs roamed Australia, the southern
desert was a huge inland sea populated by huge Mesozoic monsters and some of
the world’s most wondrous gemstones began being formed.
Opals, a
multimillion dollar exhibition by the South Australian Museum will be a
once-in-a-lifetime chance to see some of the rarest, most beautiful and
spectacular opals ever discovered in Australia.
The
exhibition’s star attraction is the Virgin Rainbow, described by museum
director Brian Oldman as ‘the most wondrous and unique opal yet discovered’.
Also on
display will be an opalised skeleton of one of the aforementioned monsters – a
6.5m plesiosaur – which died as the inland sea dried up.
The
creature – the marine reptile equivalent of a dinosaur – is named the Addyman
Plesiosaur, after its finders.
Ancient climate change
The
Addyman Plesiosaur was opalised when water and silica hardened in its bones
over millions of years.
Meanwhile
the South Australian desert became a desolate moonscape above the plesiosaur’s
forgotten carcass thanks to climate change in the Cretacious, around 100
million years ago.
It was
found by a husband and wife pair of amateur prospectors in 1968 on almost their
first day on the job.
But back
to the centrepiece of the exhibition, the 6cm long Virgin Rainbow, which is
worth over $1 million and is on display for the first time to celebrate the 100th
anniversary of the beginning of opal mining in Australia.
‘’If you
take the Virgin Rainbow – it’s almost as if there were a fire burning in there
because the movement and the colour changes are constant,’’ Oldman said.
‘’It is
perpetually different – not just if it’s under different light or the way you
hold it, but because of the way the shapes inside refract the light.’’
It is
believed the Virgin Rainbow formed from the pocket left by the bone of a dead
belemnite – a long extinct form of squid that possessed an internal skeleton.
The
gemstone, which seems to breathe a multi-hued fire of reds, gold, greens and
black, was discovered in Coober Pedy by opal miners John Dunstan, Tania Burke
and Dale Price in 2003.
‘‘You’ll
never see another piece like that one, it’s so special. That opal actually
glows in the dark — the darker the light, the more colour comes out of it, it’s
unbelievable,’’ Dunstan told the ABC recently.
‘‘I’ve
done a lot of cutting and polishing. I’ve been doing it for 50 years, but when
you compare it to the other pieces that claim to be the best ever, this one
just killed it.”
A tribute to the miners
In
addition to the amazing sights, visitors will be able to take in the smells of
an authentic Coober Pedy opal mine and an immersive display that explores the
science of opals.
“We
gathered earth from Coober Pedy and put it in a mine that we recreated from a
mould of an actual working mine as part of the exhibition,” said Oldman.
“So you
even get the smell of what it was like to be a miner – we have created an
immersive experience.
“It’s a
tribute to the ingenuity and dedication of the miners who gave their labour and
even their lives so that we can admire these amazing gems.”
Oldman
said the exhibition has quite literally been 100 million years in the making.
“That is
how long it took opals to form, from when dinosaurs walked the Earth and
central Australia was an inland sea.”
The
museum has also gathered some of the most unique and fascinating opals from
around the world to complement its own collection and showcase the beauty and
diversity of Australia’s national gemstone.
“From
jewellery to fossils, to specimens embedded in rock, visitors will be treated
to a spectacle of unmatched colour and beauty,” said Oldman.
“A range
of activities will be on offer throughout the exhibition to allow visitors to
delve into the geology and history of opals and discover the science behind
their signature play of colours.
“It will
have a rich South Australian flavour, which is unsurprising given that 90 per
cent of the world’s opals come from this state,” he said.
Finest gems gathered from around the globe
Oldman
said the international collection is a testament to the strength of the
museum’s global networks.
“It will
feature a collection of a quality never before seen in one place – this is a
once-in-a-lifetime opportunity.”
“It is
quite simply the finest collection of opals ever assembled in one place and
it’s unlikely that this collection of opals will ever be seen again.
“It tells
the whole story of opals, from how they formed, the tenacity of the miners all
the way through to the creation of opal jewellery.”
The first
opal was discovered in 1914, when a boy named Willie Hutchison went on a gold
mining expedition with his father.
“The
story goes that Willie set out in search for water one day, rather than staying
at camp as he’d been instructed to do by his father.”
“He came
back to camp with water, but also with precious opal gemstones.”
Over time
this led to the creation of opal mining communities in places like Coober Pedy,
Andamooka and Mintabie, which have remained opal mining hubs to this day.
“It is
ironic that in the most harsh of terrains the most beautiful of naturally
occurring gems are now found.”
Proof of water on Mars
When the
inland sea dried, acid levels in the top sandstone deposit were boosted,
releasing silica that would later seep into the pockets left by the bones of
long-dead plesiosaurs.
Later as
acid levels rose the silica hardened into opals. No other environment in the
world is known to have undergone this same process.
Interestingly,
just as the presence of opal reveals inland Australia’s aquatic past, the
discovery of opals on Mars confirmed the existence of water there long ago and
expanded the timeframe when water existed on the Red Planet.
The NASA
discovery back in 2008 suggested that liquid water remained on the planet’s
surface a billion years later than scientists believed, and it played an
important role in shaping the planet’s surface and possibly hosting life.
Clancy's comment: Trust me. An opal is worth seeing.
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