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Opals - Melbourne

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Opal is the national gemstone of Australia. Australian opal has often been cited as accounting for 95-97% of the world's supply of precious opal, with the state of South Australia accounting for 80% of the world's supply.
Australia produces around 97% of the world's opal; 90% is called light opal or white and crystal opal. White makes up 60% of the opal production, but cannot be found in all of the opal fields. Crystal opal or pure hydrated silica makes up 30% of the opal produced, 8% is black and only 2% is boulder opal.
Because of this, before arriving in Melbourne I had decided that I would treat myself to an opal for my birthday.
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ok, so now I need to design and make a ring to hold it!
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We came across the perfect place, Lightening Ridge Opals
Located at 175 Flinders Lane, they have a large open showroom that comfortably facilitates groups of up to 30 people. Specialising in opal, all visitors are educate with an in-depth opal lesson. A full demonstration is given to each customer and they explain the differences between each type of opal, the cutting and polishing process, and how opals are valued by their amazing colour, brightness and pattern. With over 40 years extensive experience in the opal industry, we learnt so much about the finest gemstone in the world.

The Le Souëf Family
From the arrival of Albert Le Souëf to the Australian shores in 1838, the Le Souëf family has played an integral part in the country's history. Albert became devoted to public life and held a number of offices throughout his career; he was an active member of the Board for the Protection of Aborigines, Usher of the Black Rod in the Victorian Legislative Council, and in 1882, became the director of the Zoological Gardens at Royal Park. Three of his sons, William, Ernest and Albert Sherbourne would follow in their father's footsteps and become zoological gardens directors.

William took over the directorship of the Melbourne Zoo in 1902, Ernest went on to establish the Perth Zoo in 1897, and Albert Sherbourne established the Taronga Zoo in 1916. One of William's sons, Cecil Le Souëf, nicknamed "Zoo", established an Aquarium at Rosebud in Victoria in the 1950's. He went on to discover various species of native flora and fauna, including a species of Butterfly in Victoria's North-East.

His son, Nick, graduated from Monash University and spent most of his university vacations on the Opal fields. After a brief period of teaching he decided to follow his true passion: Opals! He left the teaching profession and became a full-time Opal miner and cutter.
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He has followed his career until today, apart from a brief 2 year stint when he took over his father's Aquarium and turned it into the Rosebud Marine and Reptile Park. During this period, in the 80's, he initiated some unusual activities for the promotion of the establishment, and still holds the Australian Records of habitation in a Snake pit (3 weeks), a Shark tank (3 weeks) and a Red Back (Black Widow) Spider cage (3 weeks). There was even an appearance on the US Television show "That's Incredible". Nick currently spends his time between the Opal fields and the Melbourne store and has published his first book "What You Think is What You Get!"
After spending most of their youth "getting their hands dirty" at Lightning Ridge, the home of the Black Opal, Nick's son Jonas and daughter Atheka now run the Melbourne showroom.

Wildlife
The shop also keeps a small collection of Australian Wildlife! Including Blue-Tongue Lizards, Red Back Spider and Scorpions.
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Visitors are welcome to hold or pat our friendly lizards!
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"This family's passion has had a huge impact on our knowledge and awareness of Australian wildlife" Lisa O'Sullivan.

Formed over 100 million years ago, the Australian Opal captures the essence of natural beauty.

Formation
Opal is a type of hydrated silica, most of which was formed during the Cretaceous period between 65 -140 million years ago, in an inland sea called
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The Great Artesian Basin. It occurs to a depth of around 90 feet (30 metres) underground, in veins of about 3 feet (1 metre) called "The Opal Level". There may be up to 5 Opal levels down to 90 feet. Recent research has discovered that the drying out of Australia's landscape created conditions that trapped silica-rich gel in the host rock, which then later solidified to form opal. The transition from a tropical to an arid state about 100 million years ago provided the right circumstances for opal to form. The colour comes from the refraction of light off the microscopic silica particles.

Mining
Opal occurs in layers of 1 metre, down to around 30 metres underground, and is retrieved by basic tunnelling methods with pick and shovel and small machinery such as jackhammer and hand drill.
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Dynamite is used for blasting to access Opal producing areas. Each miner is permitted 2 claims, with a claim measuring 50 x 50 metres. This area costs around $150 per year, and the miner gets to keep whatever he finds.
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There are no large companies or corporations controlling the Opal industry. The shafts are sunk using a 3-foot Auger drill, and then loose rough Opal is brought to the surface using a hand or hydraulic winch, or a blower - a large vacuum cleaner that dumps the rough Opal into a tip truck.
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The Opal is then "puddled", or washed, to remove the loose sandstone and expose any potential colour.
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Cutting
About 2% of all Opal found is actually worth cutting.
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Most Opal is cut by hand, using Diamond tipped grinding and sanding wheels. Every cutter will have their individual preference for the wheel combination. We use 2 grinding wheels (120 & 220 grit), 2 sanding wheels (600 & 14,000 grit) and a felt polishing wheel, with cerium oxide (polish powder).
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Rough Opal is cut by hand to about 80% complete, and then adhered to a dopstick for easier cutting.
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Opal Types
the most common types of opal are black and white (milky)
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Opals are classed based on three things:
Brightness
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Colour
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Clarity
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Solid Opals
100% natural opal gemstone, except for cutting and polishing; it has not been altered in any way.

Solid White Opals
This is the most common type of opal.
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It is found mainly in Coober Pedy, South Australia. Coober Pedy is known as the Opal Capital of the world, it is the world's largest opal field. There are two types of white opal, milky and crystal. Milky opal is opaque, with the colours visible on the surface only, where as crystal opal is transparent, the colors being visible from within the depths of the stone.

Opal Doublets
A piece of solid, natural transparent or translucent-coloured opal is glued to a dark backing (usually black glass), imitating nature's solid stone.
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The dark base enhances the Opal's colour. Although some doublets can be quite valuable they are also a very cost-effective way of purchasing a beautiful Opal at less expense.

Opal Triplets
A manufactured opal consisting of three layers.
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A paper-thin slice of solid natural transparent or translucent-coloured opal is glued to a dark backing of black glass, with a dome of clear quartz crystal glued onto the top. The crystal dome is to magnify and protect the opal. A triplet is less expensive than a doublet as less opal is used.

Boulder Opals
This type of Opal is only found in the Queensland fields.
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It is opal veinlets found within ironstone boulders. The seam of opal is the face, like an opal veneer with a natural ironstone backing. Boulder Opals have a similar appearance to Black Opals but are less valuable.

Boulder Matrix Opals
This is also found in the Queensland fields, it is a mix of opal veinlets and ironstone. When these are polished, it produces an amazing assortment of stones, some looking like landscapes, others so bright the opal looks like tiny laser beams within the dark brown host rock.

Solid Black Opals
Only found in the Lightning Ridge area in the far north-northwest of New South Wales
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It is the world's rarest, most valuable, brilliant and stunning opal of them all. A layer of opal, like a band of colour, sits on a naturally occurring dark backing. It is from the colour of the backing that Black Opal gets its name. This dark background known as potch, ranges in colour from light grey through to midnight black.

Posted by charlystyles 13:16 Archived in Australia Tagged opals ligthning_ridge

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