Published: 22 August 2014
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 combination“.
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 different.
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 popular.
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 the transparency.
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. Opals are like human emotions: you always experience them different and anew.
Published: 22 August 2014
It is a fluorine aluminium silicate and comes in yellow, yellow-brown, honey-yellow, flax, brown, green, blue, light blue, red and pink ... and sometimes it has no colour at all. The topaz.
The topaz has been known for at least 2000 years and is one of the gemstones which form the foundations of the twelve gates to the Holy City of the New Jerusalem. These so-called apocalyptic stones are intended to serve in protection against enemies and as a symbol of beauty and splendour. It cannot be proved conclusively whether the name of the topaz comes from the Sanskrit or the Greek, though the Greek name 'topazos' means 'green gemstone'. The Romans dedicated the topaz to Jupiter.
The colour in which the topaz is most commonly found is yellow, and that is the colour in which it occurs in one of the major German gemstone rocks, the Schneckenstein (a topaz-bearing rock said to resemble a snail) in Saxony. In the 18th century, it was mined there during a period of over 60 years. However, most of the crystals were hardly a centimetre in diameter. You had to go to Siberia or Brazil to find crystals as large as your fist. Having said that, anyone who is interested can convince himself of the beauty of cut specimens in the topaz set in Dresden's Grünes Gewölbe (Green Vault). The enormous and magnificent topaz from the Portuguese crown, the Braganza, was for a long time thought to be a diamond. It weighs 1680 ct..
In mysticism, the topaz is attributed with a cooling, styptic and appetising effect. It is said to dispel sadness, anger and nocturnal fears, to warn its wearer of poisons and protect him or her from sudden death. It is reputed to make men handsome and intelligent and sterile women fertile and happy. However, it is probably better not to rely too much on its magical powers, since it was also claimed that you could immerse your hand in boiling water after a topaz had been thrown into it and retract it again unharmed! It is the stone of the month November.
In the Empire style, the topaz was still widespread, but then the more reasonably priced citrine took over from it and even usurped its name - gold topaz. Since then, the topaz has been a rather exotic figure in the jewellery trade, and has been given the additional predicate 'pure' to make it clear that the topaz, not the quartz topaz, is meant. And it is still waiting for its well deserved comeback to this day.
Published: 22 August 2014
From the light blue of the sky to the deep blue of the sea, aquamarines shine over an extraordinarily beautiful range of mainly light blue colours. Aquamarine is a fascinatingly beautiful gemstone. Women the world over love it for its fine blue shades which can complement almost any skin or eye colour, and creative gemstone designers are inspired by it as they are by hardly any other gem, which enables them to create new artistic cuts again and again.
Its light blue arouses feelings of sympathy, trust, harmony and friendship. Good feelings. Feelings which are based on mutuality and which prove their worth in lasting relationships. The blue of aquamarine is a divine, eternal colour, because it is the colour of the sky. However, aquamarine blue is also the colour of water with its life-giving force. And aquamarine really does seem to have captured the lucid blue of the oceans. No wonder, when you consider that according to the saga it originated in the treasure chest of fabulous mermaids, and has, since ancient times, been regarded as the sailors' lucky stone. Its name is derived from the Latin 'aqua' (water) and 'mare' (sea). It is said that its strengths are developed to their best advantage when it is placed in water which is bathed in sunlight. However, it is surely better still to wear aquamarine, since according to the old traditions this promises a happy marriage and is said to bring the woman who wears it joy and wealth into the bargain. An ideal gem, not only for loving and married couples.
A gemstone with many good qualities
Aquamarine is one of our most popular and best-known gemstones, and distinguishes itself by many good qualities. It is almost as popular as the classics: ruby, sapphire and emerald. In fact it is related to the emerald, both belonging to the beryl family. The colour of aquamarine, however, is usually more even than that of the emerald. Much more often than its famous green cousin, aquamarine is almost entirely free of inclusions. Aquamarine has good hardness (7.5 to 8 on the Mohs scale) and a wonderful shine. That hardness makes it very tough and protects it to a large extent from scratches. Iron is the substance which gives aquamarine its colour, a colour which ranges from an almost indiscernible pale blue to a strong sea-blue. The more intense the colour of an aquamarine, the more value is put on it. Some aquamarines have a light, greenish shimmer; that too is a typical feature. However, it is a pure, clear blue that continues to epitomise the aquamarine, because it brings out so well the immaculate transparency and magnificent shine of this gemstone.
'Santa Maria' sets pulses racing
The bright blue of this noble beryl is making more and more friends. The various colour nuances of aquamarine have melodious names: the rare, intense blue aquamarines from the Santa Maria de Itabira mine in Brazil, which make every gemstone lover's heart beat faster, are called 'Santa Maria'. Similar nuances come from a few gemstone mines in Africa, particularly Mozambique. To help distinguish them from the Brazilian ones, these aquamarines have been given the name 'Santa Maria Africana'. The 'Espirito Santo' colour of aquamarines from the Brazilian state of that name is of a blue that is not quite so intense. Yet other qualities are embodied in the stones from Fortaleza and Marambaia. One beautiful aquamarine colour was named after the Brazilian beauty queen of 1954, and has the name 'Martha Rocha'.
It can be seen from the names of aquamarine colours just how important Brazil is among the countries where aquamarine is found. Most of the raw crystals for the world market come from the gemstone mines of that large South American country. Every now and then, large aquamarine crystals of immaculate transparency are also found with a magnificent colour, a combination which is very unusual in gemstones. And very occasionally, sensationally large aquamarine crystals come to light in Brazil, such as the crystal of 110.5 Kg found in 1910 in Marambaia/Minas Gerais, or for example the 'Dom Pedro', weighing 26 Kg and cut in Idar-Oberstein in 1992 by the gemstone designer Bernd Munsteiner, the largest aquamarine ever to have been cut. However, aquamarines are also found in other countries, for example Nigeria, Zambia, Madagascar, Mozambique, Afghanistan and Pakistan.
Favourite stone of modern designers
There is hardly any other gemstone in modern jewellery design which is refined in such a variety of ways as aquamarine. Whether it is fashioned as a clear, transparent gem in the classical step cut, or creatively cut in a more modern design, it is always fascinatingly beautiful. Uncut too, or with many inclusions which can be brought into play by the designer in the way in which the stone is cut, it can be refined to produce the most beautiful creations. Designers call it their favourite gemstone. Again and again they take the world by surprise with a new, modern artistic cut, and when they are breaking new ground, aquamarine is a gem that they particularly like to work with. Without doubt, these creative designer cuts have contributed to the great popularity of this gem. The lucid colour of aquamarine makes it easy to see inclusions. For this reason, aquamarine should always be of the greatest possible transparency. On the other hand, particularly charming effects can sometimes be achieved in the way the gemstone is cut by bringing the inclusions into play. The light colour of aquamarine leaves the gemstone designer free to bring out the brilliance of the gem with fine grooves, notches, curves and edges. In this way, each aquamarine becomes a unique specimen, whose magical attraction no woman can resist.
Published: 22 August 2014
The vivid green of the peridot, with just a slight hint of gold, is the ideal gemstone colour to go with that light summer wardrobe. No wonder – since the peridot is the gemstone of the summer month of August.
The peridot is a very old gemstone, and one which has become very popular again today. It is so ancient that it can be found in Egyptian jewellery from the early 2nd millennium B.C.. The stones used at that time came from a deposit on a small volcanic island in the Red Sea, some 45 miles off the Egyptian coast at Aswan, which was not rediscovered until about 1900 and has, meanwhile, been exhausted for quite some time. Having said that, the peridot is also a thoroughly modern gemstone, for it was not until a few years ago that peridot deposits were located in the Kashmir region; and the stones from those deposits, being of an incomparably beautiful colour and transparency, have succeeded in giving a good polish to the image of this beautiful gemstone, which had paled somewhat over the millennia.
The ancient Romans too were fond of this gemstone and esteemed its radiant green shine, which does not change even in artificial light. For that reason they nicknamed it the 'emerald of the evening'. Peridot is also found in Europe in medieval churches, where it adorns many a treasure, for example one of the shrines in Cologne Cathedral. During the baroque period, the rich green gemstone once again enjoyed a brief heyday, and then it somehow faded into oblivion.
Spectacular 'Kashmir peridots'
But suddenly, in the middle of the 1990s, the peridot was the big sensation at gemstone fairs all round the world. The reason? In Pakistan, up on an inhospitable pass at some 4000 metres (13,120 ft.), a sensationally rich deposit of the finest peridots had been found. In tough climatic conditions which permitted the gemstones to be mined only during the summer months, the unusually large, fine crystals and fragments were brought down into the valley. These stones were finer than anything that had ever been seen before. And the deposits were so rich that the demand for peridots can, for the present, easily be satisfied.
In order to emphasise the special quality of the peridots from Pakistan, these stones are offered as 'Kashmir peridots', following the famous Kashmir sapphires. Creative gemstone cutters have succeeded in cutting some fascinatingly beautiful one-off stones of more than 100 carats from some of the large, fine, clear crystals with their magnificent rich green!
How green? It all depends on the iron
This gemstone has no fewer than three names: 'peridot', 'chrysolite', from the Greek 'gold stone', and 'olivine', for the peridot is the gemstone form of the mineral olivine. In the gemstone trade it is called 'peridot', derived from the Greek word 'peridona', which means something like 'to give richness'.
The peridot is one of the few gemstones which come in one colour only. The rich, green colour with the slight tinge of gold is caused by very fine traces of iron. From a chemical point of view, peridot is an iron magnesium silicate. The intensity of the colour depends on the amount of iron actually present. The colour itself can vary over all shades of yellowish green and olive, and even to a brownish green. Peridot is not particularly hard - only 6.5 to 7 on the Mohs scale - but it is easy to look after and fairly robust. Peridot cat's eyes and star peridot are particularly rare and precious.
The most beautiful stones come from the border area between Pakistan and Afghanistan. However, the peridot as a gemstone also exists in Myanmar, China, the USA, Africa and Australia. Stones from East Burma, now known as Myanmar, have a vivid light green and fine inclusions with a silky shine to them. Peridot from Arizona, where it is popularly used in native American jewellery, often has somewhat yellowish or gold-brown nuances.
Uncomplicated, but not for the cutter
The peridot is cut in accordance with its crystal shape, mostly faceted or in classical table cuts, or round, antique, as an octahedron or oval. Smaller crystals are cut into standardised series stones, larger ones into imaginative one-offs. Cabochons are made if the material contains more inclusions, for the domed cut brings out the fine silky shine of the inclusions to their best.
The cutters know full well that this gemstone is anything but easy to work with. The raw crystals can be very tricky and may crack easily. There is often a good deal of tension on the inside of the crystal. But once the cutter has succeeded in removing the coarser inclusions, the peridot is a precious stone with good wearing qualities which does not call for any special care.
An ideal summer stone
The peridot adds a wonderful variant to the colour spectrum of green gemstones. Increasingly, it is processed not only to one-offs, but also for use in series jewellery. And since the world of fashion is just in the process of rediscovering its love for the colour green, the popularity of this rich green gemstone is also very much on the up.
Thanks to the rich finds in Pakistan and Afghanistan, there is enough raw material on the market, so the 'right stone' can now be found to cater for each individual taste and each pocket. Large, transparent stones of an intense colour are, however, rare and correspondingly expensive. The peridot is a gemstone that you should definitely get to know better. Its fine pistachio to olive green is the perfect complement to a fresh, light summer wardrobe.
Published: 22 August 2014
Tanzanite is an extraordinary gemstone. It occurs in only one place worldwide. Its blue, surrounded by a fine hint of purple, is a wonderful colour. Thanks to its unusual aura and the help of the New York jeweller's Tiffany, it has rapidly become one of the most coveted gemstones in the world.
It is named after the East African state of Tanzania, the only place in the world where it has been found. Africa? Does anyone think of gemstones when they hear that name? Well they should, because Africa is a continent which provides the world with a multitude of truly magnificent gemstones, like tanzanite for example. On its discovery in 1967, it was enthusiastically celebrated by the specialists as the 'gemstone of the 20th century'. They held their breath in excitement as they caught sight of the first deep-blue crystals which had been found in the Merelani Hills near Arusha in the north of Tanzania. Millions of years ago, metamorphic schists, gneisses and quartzites formed impressive, flat-topped inselbergs on a vast plain in the shadow of Kilimanjaro. The precious crystals grew in deposits on the inside of these unusual elevations. For a long, long time they were hidden from the eye of Man, until one day some passing Masai shepherds noticed some sparkling crystals lying in the sun and took them along with them.
In Merelani today, the search is carried on for the coveted crystals in several, smallish mines, in some cases using modern methods. As a rule, only small grains are found, but now and again the mineworkers succeed in fetching out a larger crystal – to the joy of the mine owners and that of the large number of tanzanite fans.
The tanzanite trade is in the hands of many licensed merchants, mostly on a small scale, who have, over the decades, built up stable, trusting business relationships with gemstone companies in India, Germany, Israel and the USA. An estimated 90 per cent of all tanzanite merchants are official members of the International Colored Gemstone Association ICA, and are thus bound by the high ethical standards of that organisation. In this way, this exclusive gemstone is not subject to trade via dubious channels, but instead, in spite of its rarity, passed on along reputable trade routes to established cutting-centres and subsequently to major jewellers all round the world.
Really just a blue zoisite ...
Tanzanite is a blue variety of the gemstone zoisite. It consists of calcium aluminium silicate and is not particularly hard, having a value of 6.5 to 7 on the Mohs scale. For that reason, it should always be worn carefully and never placed in an ultrasonic bath for cleaning or brought into contact with acids.
When the first tanzanites were offered to the New York jewellery company Tiffany a short time after their discovery, they sparked an enthusiastic reaction. 'This gemstone is a sensation!', they said. However, they did make a recommendation to give the 'child' another name, since the gemmologically correct name 'blue zoisite' was felt to be too close to the English word 'suicide'. So Tiffany's proposed the name 'tanzanite', after the place where the stone had been found - a name which quickly came into general use in the trade. And it was Tiffany's who, two years after its discovery, presented the exclusive gemstone to the general public with a broad-based advertising campaign.
... but what a fantastic colour!
The deep blue of the tanzanite is fantastic, and runs from ultramarine blue to light violet-blue. The most coveted colour is a blue surrounded by a delicate hint of purple, which has a particularly wonderful effect in sizes of over 10 carats. The well developed polychromaticity of the tanzanite is typical: depending on the angle from which you look at it, the stone may appear blue, purple or brownish-yellow. Having said that, most raw crystals are somewhat spoiled by a brownish-yellow component, though it can be made to disappear by the cutter if he heats the stone carefully in an oven to approximately 500°. During the procedure he must pay careful attention to the moment at which the colour turns to blue. This burning is a method of treatment which is regarded as customary in the trade, but the raw stones must be as free of inclusions as possible, since otherwise fissures may occur. In fact working with tanzanite can sometimes give even the most experienced cutter a bit of a headache, the cleavage of this gemstone being very pronounced in one direction. This exclusive gemstone is cut in every imaginable shape from the classical round shape to a number of imaginative designer cuts.
A tanzanite will continue to fascinate with its unusual, captivating aura. Its deep blue with the slightly purple tinge is one of the most extravagant colours known to Man. It personifies immaculate, yet unconventional elegance. A person who acquires one of these exclusive gems is someone who wishes to set himself apart from the hoi polloi. A person who wears it exudes confidence and individuality. The almost magical colour of a perfectly cut tanzanite is one that not only suits confident young women; it is also excellently suited to underlining the individuality of the more mature woman.
In the meantime, almost any price you care to name is being asked - and paid! - for tanzanites of good quality and large size. What makes this stone so popular? Is it simply that fantastic colour? No, it is also the exclusivity of its origin. The stone is particularly highly prized because it is found in only one place in the whole world. The idea of possessing something that not everyone has has always been one of the main criteria in the way we esteem special gems.