Australia's National Gem - The Opal
Some Australian Aboriginal people call it 'The Rainbow Stone' , but others say it is 'Tears to the Eyes' because that is the effect that this most remarkable gift of nature has on those who find it and are drawn to it by the incredible ability of the gem to expose an infinite number of colours, forever moving with the light.
In one of the most harsh environments imaginable, the opal miner toils, digging around in temperatures of up to 55 degrees Celsius and 98% humidity. That makes mining not only uncomfortable, but at times life threatening. Dehydration is a constant threat for the unwary, and impaired judgement caused by excessive heat makes life even more dangerous for those descending in to hand dug shafts or operating the heavy machinery on the large open mine cuts. Add to this the possibility that all the work may well be for little or no result and you've got a very special character that lives and works in these regions.
It is as much the call of the outback that lures the opal miner and keeps him going: scorched landscapes and blazing red sunsets; the night stars from horizon to horizon; a hauntingly beautiful country that penetrates one's soul.
In the early days there was no particular method for determining where to dig for opals. The tale is told that once surface indicators showed a possibility of finding the gem, a hat was thrown high into the air. Carried by the hot desert winds, wherever the hat landed, that's where you dig!
These days, however, with aerial photography to identify faults in the landscape (which are likely sites) and bore holes drilled to assess the potential, the gamble is not quite so 'hit and miss'. When a site is selected, machinery is brought in to excavate to just above what is called 'level'. This is the depth at which opal may be found, and can be as far down as 20 metres. At this point some material is removed and carefully inspected for opal. Of course, there is no guarantee of finding 'colour', and it is not surprising to learn that only ten percent of opal miners find it profitable.
As one miner put it, "Opal is made up of seven elements - silica, aluminium, manganese, nickel, iron, water ... and bloody good luck!"
The elusive opal was formed many years ago when liquid silica filtered down into the faults and fissures of sedimentary rock. When the water content evaporated, tiny spheres of silica remained and over time were solidified. Low grade or 'potch' opal (95% of what is found) is composed of irregularly placed spheres which produce little or no colour. But high grade opal (only 5% of what is found) has regularly placed spheres which allow light to be diffracted through them to produce the spectacular colours. The size of the spheres determines the colours, with the larger ones producing the fiery reds so sought after.
There are two basic varieties of opals mined in Australia - Seam Opal and Boulder Opal. The difference being that seam opal is found unattached or free in the ground, whereas boulder opal is attached to or within a host ironstone or sandstone rock. Both seam opal and boulder opal are categorized into three types:
- Black opal: Black referring to the dark grey, blue or black body colour that provides a striking contrast for the kaleidoscope of colour in the transparent to translucent crystals.
- Crystal opal: This being translucent to semi transparent without a grey or milky background and showing brilliant colours from a glossy background.
- Light Opal: This is more subdued with a spectrum of colours emanating from a white or light to milky background colour.
The value of the opal depends on the amount and brilliance of the colour, preferably being evenly distributed across the face of the polished opal. The greater the spectrum of colours from red to violet the better, with crimson, reds, and orange being rarer than the greens and blues. Milkiness, cloudiness or greyness detracts from the value.
Basically the greater the number of colours, the more prized the gem and if these are arranged in a block pattern, more value is added. The extremes are tiny pin sized dots of colour (pinfire) to one large sheet of colour (broadflash) covering the whole stone. The elusive 'harlequin' is the ultimate in this form but is very rare. A pattern in proportion to the size of the gem is desirable and each opal is individual. It may have a play of colours which is attractive in its own right or it may display a natural outback landscape scene.
Shapes of the finished opal vary considerably according to the characteristics of each stone. Boulder Opal is usually cut in baroque or free form, whereas seam opal is at its best presented in cabochon (domed) form.
If you are buying an unset opal, it is important to consider the way it will eventually be worn. For example, some opals will offer a better play of colour when worn vertically as in brooch or pendant, whereas others are best flat as in a ring setting. There is a great deal to consider when investing in your opal, but expert advice is available for your complete pleasure and pride in an ever-inspiring piece of jewellery.
Australian Pink Diamonds
There is one diamond that stands alone; one diamond that creates excitement and competition to own; one diamond that continues to command strong prices ... the Argyle pink diamond.
The Argyle Diamond Mine has been the world's leading volume producer of diamonds since 1986 when its operation in the remote Kimberley region of Western Australia went into full production. Each year it produces approximately 30 million carats of diamonds, which is approximately one quarter of the world's total.
The diamonds produced by Argyle are found in a range of colours including white, champagne and pink. Argyle is the world's primary source of rare pink diamonds, which have become the company's signature stone.
The pink diamond is believed to have been created through structural pressures exerted on carbon molecules during diamond formation up to three billion years ago, and have been found in India, Brazil and Africa.
Pink diamonds are recovered in a range of shades from light rose to full-bodied purple-reds, and are polished in a wide range of sizes and shapes. Prices are dictated by the intensity of colour and significant pink diamonds are sold with certification from the leading grading authorities.
The ultimate glory of the stone comes in the cutting and polishing and the Argyle pinks are processed in Perth, Western Australia. The work of cutting and polishing is so delicate and exacting that eventually the artisan is able to tell, simply by rolling a stone in their fingers, whether or not it is perfectly rounded.
The beauty and the attraction of the Argyle pinks is immediately evident and overpowering and it is easy to understand how, for some people, they become an addiction, an object of adoration.
Argyle pink diamonds are available only at the finest jewellers.
Australian South Sea Pearls
Mankind has long held the fascination with the mystique and lustre of the pearl. The Australian South Sea pearl, which is the most precious of all pearls, comes to life in the pristine ocean waters of North Western Australia.
The miracle of nature is in its ability to never duplicate any of its creations. No two pearls are alike; and each is unique as the individual wearing them. Each pearl is judged on five special qualities. No quality, however, is to be considered without the others. Consideration of each makes for an informed decision.
Lustre - The distinctive characteristic, or great beauty of a pearl is its lustre (or orient). Lustre is a subdued iridescence and is the most important consideration when selecting a pearl. Lustre should be bright - never dull. While much attention is devoted to the remarkable size of these pearls, what really sets them apart is their exquisitely thick, creamy nacre which possesses an unmistakeable gentle deep glow.
Size - South Sea pearls are renowned for their size. All things being equal, the larger the pearl the greater the value. Sizes range from 9mm to 16mm and rarely reach 20mm and above.
Shape - South Sea pearls are varied in their form. Perfectly round pearls and perfect teardrops are extremely rare and therefore highly prized. This does not mean that other shapes do not have their own unique charm and value. Because of the thickness of the South Sea pearl nacre, pearls are found in an array of sizes and shapes, including round, semi-round, button, circled, oval, drop, semi-baroque and baroque.
Colour - South Sea pearls are highly desired for the subtle richness of their natural colours. From luminescent whites to sparkling golds, the stunning range of natural colours of South Sea pearls must be seen to be believed. While colour is not normally an indicator of the quality of South Sea pearls, premium prices are fetched for pearls displaying unusually beautiful orients of coloured overtones such as White Pink, Silver Pink and Deep Gold.
Surface - It is rare to find a pearl free from any surface blemishes - these are after all, gems created by nature. The most beautiful and valuable pearls may still have slight imperfections. These appear in the form of small pits or dimples. It is these 'beauty marks' that nature bestows, which makes each pearl unique. However, when found, a flawless surface will increase the value of a pearl significantly.
Shopping for Australian Opals, Pink Diamonds & South Sea Pearls:
iOnline