Friday, June 5, 2009

THE GEMSTONES

A gemstone is the naturally occurring crystalline form of a mineral, which is desirable for its beauty, valuable in its rarity and durable enough to be enjoyed for generations.

There are more than 40 popular gem varieties and many more rare collector gemstones. Although some gemstone varieties have been treasured since before history began and others were only discovered recently, they are all nature's gifts to us, and our gifts to our children.

Instead of choosing by variety, you might want to choose a gemstone by color. Some varieties also come in a range of colors. Are you particularly fond of sapphires? Are you looking for something in orange? Either way, you will be surprised by the number of choices.

Gemstones are among the most individual of nature's creations: perfect crystals, with no two alike. Below, we list some of the most popular gemstone varieties but there are many more rare collector's gemstones.

Read More......

Wednesday, May 20, 2009

RUBY

Which colour would you spontaneously associate with love and vivacity, passion and power? It's obvious, isn't it? Red. Red is the colour of love. It radiates warmth and a strong sense of vitality. And red is also the colour of the ruby, the king of the gemstones. In the fascinating world of gemstones, the ruby is the undisputed ruler.

For thousands of years, the ruby has been considered one of the most valuable gemstones on Earth. It has everything a precious stone should have: magnificent colour, excellent hardness and outstanding brilliance. In addition to that, it is an extremely rare gemstone, especially in its finer qualities.

For a long time India was regarded as the ruby's classical country of origin. In the major works of Indian literature, a rich store of knowledge about gemstones has been handed down over a period of more than two thousand years. The term 'corundum', which we use today, is derived from the Sanskrit word 'kuruvinda'. The Sanskrit word for ruby is 'ratnaraj', which means something like 'king of the gemstones'. And it was a royal welcome indeed which used to be prepared for it. Whenever a particularly beautiful ruby crystal was found, the ruler sent high dignitaries out to meet the precious gemstone and welcome it in appropriate style. Today, rubies still decorate the insignia of many royal households. But are they really all genuine rubies? Read on to find out more!

Only a little bit of chrome ...
Ruby is the red variety of the mineral corundum, one of the hardest minerals on Earth, of which the sapphire is also a variety. Pure corundum is colourless. Slight traces of elements such as chrome, iron, titanium or vanadium are responsible for the colour. These gemstones have excellent hardness. On the Mohs scale their score of 9 is second only to that of the diamond. Only red corundum is entitled to be called ruby, all other colours being classified as sapphires. The close relationship between the ruby and the sapphire has only been known since the beginning of the 19th century. Up to that time, red garnets or spinels were also thought to be rubies. (That, indeed, is why the 'Black Ruby' and the 'Timur Ruby', two of the British Crown Jewels, were so named, when they are not actually rubies at all, but spinels).

Ruby, this magnificent red variety from the multi-coloured corundum family, consists of aluminium oxide and chrome as well as very fine traces of other elements - depending on which deposit it was from. In really fine colours and good clarity, however, this gemstone occurs only very rarely in the world's mines. Somewhat paradoxically, it is actually the colouring element chrome which is responsible for this scarcity. True enough, millions of years ago, when the gemstones were being created deep inside the core of the Earth, chrome was the element which gave the ruby its wonderful colour. But at the same time it was also responsible for causing a multitude of fissures and cracks inside the crystals. Thus only very few ruby crystals were given the good conditions in which they could grow undisturbed to considerable sizes and crystallise to form perfect gemstones. For this reason, rubies of more than 3 carats in size are very rare. So it is no wonder that rubies with hardly any inclusions are so valuable that in good colours and larger sizes they achieve top prices at auctions, surpassing even those paid for diamonds in the same category.

Some rubies display a wonderful silky shine, the so-called 'silk' of the ruby. This phenomenon is caused by very fine needles of rutile. And now and then one of the rare star rubies is found. Here too, the mineral rutile is involved: having formed a star-shaped deposit within the ruby, it causes a captivating light effect known by the experts as asterism. If rubies of this kind are cut as half-dome shaped cabochons, the result is a six-spoked star which seems to glide magically across the surface of the stone when the latter is moved. Star rubies are precious rarities. Their value depends on the beauty and attractiveness of the colour and, though only to a lesser extent, on their transparency. Fine star rubies, however, should always display rays which are fully formed all the way to the imaginary horizontal line which runs through the middle of the stone, and the star itself should be situated right in the centre.

Ruby-red means passion
Red for ruby. Ruby-red. The most important thing about this precious stone is its colour. It was not for no reason that the name 'ruby' was derived from the Latin word 'rubens', meaning 'red'. The red of the ruby is incomparable: warm and fiery. Two magical elements are associated with the symbolism of this colour: fire and blood, implying warmth and life for mankind. So ruby-red is not just any old colour, no, it is absolutely undiluted, hot, passionate, powerful colour. Like no other gemstone, the ruby is the perfect way to express powerful feelings. Instead of symbolising a calm, controlled affection, a ring set with a precious ruby bears witness to that passionate, unbridled love that people can feel for each other.

Birthplaces of fine rubies
Which is the most beautiful ruby-red? Good question. The red of a ruby may involve very different nuances depending on its origin. The range of those nuances is quite wide, and could perhaps be compared to hotel categories, from luxury accommodation down to a plain inn or hostel. For example, if the gemstone experts refer to a 'Burmese ruby', they are talking about the top luxury category. However, it does not necessarily follow that the stone is of Burmese origin. It is basically an indication of the fact that the colour of the ruby in question is that typically shown by stones from the famous deposits in Burma (now Myanmar): a rich, full red with a slightly bluish hue. The colour is sometimes referred to as 'pigeon-blood-red', but the term 'Burmese colour' is a more fitting description. A connoisseur will immediately associate this colour with the legendary 'Mogok Stone Tract' and the gemstone centre of Mogok in the North of Myanmar. Here, the country's famous ruby deposits lie in a mountain valley surrounded by high peaks. Painstakingly, gemstones of an irresistible luminosity are brought to light in the 'valley of the rubies'. Unfortunately, really fine qualities are quite rare even here. The colour of a Burmese ruby is regarded as exceptionally vivid. It is said to display its unique brilliance in any light, be it natural or artificial.

The journey to the world's most important ruby deposits takes us further on to the small town of Mong Hsu in the North-East of Myanmar, where the most important ruby deposits of the nineties lie. Originally, it was believed that these rubies would hardly prove suitable for use in jewellery, since untreated Mong Hsu ruby crystals actually display two colours: a purple to black core and a bright red periphery. Only when it had been discovered that the dark core could be turned into deep red by means of heat treatment did rubies from Mong Hsu begin to find their way on to the jewellery market. Today, the Mong Hsu gemstone mines are still among the most important ruby suppliers. In the main, they offer heat-treated rubies in commercial qualities and sizes between 0.5 and 3 carats.

Ruby deposits also exist in neighbouring Vietnam, near the Chinese border. Rubies of Vietnamese origin generally display a slightly purplish hue. Rubies from Thailand, another classical supplier, however, often have a darker red which tends towards brown. This 'Siamese colour' - an elegantly muted deep red - is considered second in beauty only to the Burmese colour, and is especially popular in the USA. Ceylon rubies, which have now become very rare, are mainly light red, like ripe raspberries.

Other ruby deposits are located in Northern Pakistan in the Hunza Valley, Kashmir, Tadzhikistan, Laos, Nepal, and Afghanistan. But rubies are also produced in India, where deposits with relatively large crystals were discovered in the federal states of Mysore and Orissa. These crystals have many inclusions, but they are, nevertheless, eminently suited to being cut as beads or cabochons.

Lately, people have begun to talk about East Africa as a source of rubies. Straight after their discovery in the 1960s, rubies from Kenya and Tanzania surprised the experts by their beautiful, strong colour, which may vary from light to dark red. But in the African mines too, fine and clear rubies of good colour, purity and size are very rare. Usually the qualities mined are of a merely average quality.

Colour above (almost) everything
As we have said, colour is a ruby's most important feature. Its transparency is only of secondary importance. So inclusions do not impair the quality of a ruby unless they decrease the transparency of the stone or are located right in the centre of its table. On the contrary: inclusions within a ruby could be said to be its 'fingerprint', a statement of its individuality and, at the same time, proof of its genuineness and natural origin. The cut is essential: only a perfect cut will underline the beauty of this valuable and precious stone in a way befitting the 'king of the gemstones'. However, a really perfect ruby is as rare as perfect love. If you do come across it, it will cost a small fortune. But when you have found 'your' ruby, don't hesitate: hang on to it!

Read More......

EMERALD

Emeralds are fascinating gemstones. They have the most beautiful, most intense and most radiant green that can possibly be imagined: emerald green. Inclusions are tolerated. In top quality, fine emeralds are even more valuable than diamonds.

The name emerald comes from the Greek 'smaragdos' via the Old French 'esmeralde', and really just means 'green gemstone'. Innumerable fantastic stories have grown up around this magnificent gem. The Incas and Aztecs of South America, where the best emeralds are still found today, regarded the emerald as a holy gemstone. However, probably the oldest known finds were once made near the Red Sea in Egypt. Having said that, these gemstone mines, already exploited by Egyptian pharaohs between 3000 and 1500 B.C. and later referred to as 'Cleopatra's Mines', had already been exhausted by the time they were rediscovered in the early 19th century.

Written many centuries ago, the Vedas, the holy scriptures of the Indians, say of the precious green gems and their healing properties: 'Emeralds promise good luck ...'; and 'The emerald enhances the well-being ...'. So it was no wonder that the treasure chests of Indian maharajas and maharanis contained wonderful emeralds. One of the world's largest is the so-called 'Mogul Emerald'. It dates from 1695, weighs 217.80 carats, and is some 10cm tall. One side of it is inscribed with prayer texts, and engraved on the other there are magnificent floral ornaments. This legendary emerald was auctioned by Christie's of London to an unidentified buyer for 2.2m US Dollars on September 28th 2001.


Emeralds have been held in high esteem since ancient times. For that reason, some of the most famous emeralds are to be seen in museums and collections. The New York Museum of Natural History, for example, has an exhibit in which a cup made of pure emerald which belonged to the Emperor Jehangir is shown next to the 'Patricia', one of the largest Colombian emerald crystals, which weighs 632 carats. The collection of the Bank of Bogota includes five valuable emerald crystals with weights of between 220 and 1796 carats, and splendid emeralds also form part of the Iranian National Treasury, adorning, for example, the diadem of the former Empress Farah. The Turkish sultans also loved emeralds. In Istanbul's Topkapi Palace there are exhibits with items of jewellery, writing-implements and daggers, each lavishly adorned with emeralds and other gems.

The green of life and of love
The green of the emerald is the colour of life and of the springtime, which comes round again and again. But it has also, for centuries, been the colour of beauty and of constant love. In ancient Rome, green was the colour of Venus, the goddess of beauty and love. And today, this colour still occupies a special position in many cultures and religions. Green, for example, is the holy colour of Islam. Many of the states of the Arab League have green in their flags as a symbol of the unity of their faith. Yet this colour has a high status in the Catholic Church too, where green is regarded as the most natural and the most elemental of the liturgical colours.

The magnificent green of the emerald is a colour which conveys harmony, love of Nature and elemental joie de vivre. The human eye can never see enough of this unique colour. Pliny commented that green gladdened the eye without tiring it. Green is perceived as fresh and vivid, never as monotonous. And in view of the fact that this colour always changes somewhat between the bright light of day and the artificial light of a lamp, emerald green retains its lively vigour in all its nuances.

Fingerprints of nature
The lively luminosity of its colour makes the emerald a unique gemstone. However, really good quality is fairly rare, with inclusions often marring the evenness of the colour – signs of the turbulent genesis which has characterised this gemstone. Fine inclusions, however, do not by any means diminish the high regard in which it is held. On the contrary: even with inclusions, an emerald in a deep, lively green still has a much higher value than an almost flawless emerald whose colour is paler. Affectionately, and rather poetically, the specialists call the numerous crystal inclusions, cracks or fissures which are typical of this gemstone 'jardin'. They regard the tender little green plants in the emerald garden as features of the identity of a gem which has grown naturally.
So where do they come from and how is it that they exist at all? In order to answer these questions, we need to look far, far back into the time of the emerald's origin. Emeralds from Zimbabwe are among the oldest gemstones anywhere in the world. They were already growing 2600 million years ago, whilst some specimens from Pakistan, for example, are a mere 9 million years young. From a chemical-mineralogical point of view, emeralds are beryllium-aluminium-silicates with a good hardness of 7.5 to 8, and belong, like the light blue aquamarine, the tender pink morganite, the golden heliodor and the pale green beryl, to the large gemstone family of the beryls. Pure beryl is colourless. The colours do not occur until traces of some other element are added. In the case of the emerald, it is mainly traces of chromium and vanadium which are responsible for the fascinating colour. Normally, these elements are concentrated in quite different parts of the Earth's crust to beryllium, so the emerald should, strictly speaking, perhaps not exist at all. But during intensive tectonic processes such as orogenesis, metamorphism, emergences and erosion of the land, these contrasting elements found each other and crystallised out to make one of our most beautiful gemstones. The tension involved in the geological conditions conducive to the above processes produced some minor flaws, and some major ones. A glance through the magnifying-glass or microscope into the interior of an emerald tells us something about the eventful genesis of this unique gem: here we see small or large fissures; here the sparkle of a mini-crystal or a small bubble; here shapes of all kinds. While the crystals were still growing, some of these manifestations had the chance to 'heal', and thus the jagged three-phase inclusions typical of Colombian emeralds were formed: cavities filled with fluid, which often also contain a small bubble of gas and some tiny crystals.

Logically enough, a genesis as turbulent as that of the emerald impedes the undisturbed formation of large, flawless crystals. For this reason, it is only seldom that a large emerald with good colour and good transparency is found. That is why fine emeralds are so valuable. But for the very reason that the emerald has such a stormy past, it is surely entitled to show it - that is, as long as only a fine jardin is to be seen, and not a rank garden which spoils both colour and transparency.

The world of fine emeralds
Colombia continues to be at the top of the list in terms of the countries in which fine emeralds are found. It has about 150 known deposits, though not all of these are currently being exploited. The best known names are Muzo and Chivor, where emeralds were mined by the Incas in pre-Columbian times. In economic terms, the most important mine is at Coscuez, where some 60 faces are being worked. According to estimates, approximately three quarters of Colombia's emerald production now comes from the Coscuez Mine. Colombian emeralds differ from emeralds from other deposits in that they have an especially fine, shining emerald green unimpaired by any kind of bluish tint. The colour may vary slightly from find to find. This fascinatingly beautiful colour is so highly esteemed in the international emerald trade that even obvious inclusions are regarded as acceptable. But Colombia has yet more to offer: now and then the Colombian emerald mines throw up rarities such as Trapiche emeralds with their six rays emanating from the centre which resemble the spokes of a millwheel.

Even if many of the best emeralds are undisputedly of Colombian origin, the 'birthplace' of a stone is never an absolute guarantee of its immaculate quality. Fine emeralds are also found in other countries, such as Zambia, Brazil, Zimbabwe, Madagascar, Pakistan, India, Afghanistan and Russia. Zambia, Zimbabwe and Brazil in particular have a good reputation for fine emeralds in the international trade. Excellent emerald crystals in a beautiful, deep emerald green and with good transparency come from Zambia. Their colour is mostly darker than that of Colombian emeralds and often has a fine, slightly bluish undertone. Emeralds which are mostly smaller, but very fine, in a vivacious, intense green come from Zimbabwe's famous Sandawana Mine, and they often have a delicate yellowish-green nuance. And the famous emerald mines of Colombia currently face competition from right next door: Brazil's gemstone mine Nova Era also produces emeralds in beautiful green tones, and if they are less attractive than those of their famous neighbour it is only by a small margin. Brazil also supplies rare emerald cat's eyes and extremely rare emeralds with a six-spoked star. Thanks to the finds in Africa and Brazil, there are more emeralds on the market now than there used to be - to the delight of emerald enthusiasts –

A sophisticated gemstone
Whilst its good hardness protects the emerald to a large extent from scratches, its brittleness and its many fissures can make cutting, setting and cleaning rather difficult. Even for a skilled gem cutter, cutting emeralds presents a special challenge, firstly because of the high value of the raw crystals, and secondly because of the frequent inclusions.

However, this does not detract from the cutters' love of this unique gem. Indeed, they have developed a special cut just for this gem: the emerald cut. The clear design of this rectangular or square cut with its bevelled corners brings out the beauty of this valuable gemstone to the full, at the same time protecting it from mechanical strain.

Emeralds are also cut in many other, mainly classical shapes, but if the raw material contains a large number of inclusions, it may often be cut into a gently rounded cabochon, or into one of the emerald beads which are so popular in India.

Today, many emeralds are enhanced with colourless oils or resins. This is a general trade practice, but it does have the consequence that these green treasures react very sensitively to inappropriate treatment. For example, they cannot be cleaned in an ultrasonic bath. The substances that may have been used by the cutter during his work, or applied subsequently, seal the fine pores in the surface of the gem. Removing them will end up giving the stone a matt appearance. For this reason, emerald rings should always be taken off before the wearer puts his or her hands in water containing cleansing agent.

A matter of trust
Unfortunately, because the emerald is not only one of the most beautiful gemstones, but also one of the most valuable, there are innumerable synthetics and imitations. So how can you protect yourself from these 'fakes'? Well, the best way is to buy from a specialist in whom you have confidence. Large emeralds in particular should only be purchased with a report from a reputable gemmological institute. Such an institute will be able, thanks to the most modern examination techniques, to differentiate reliably between natural and synthetic emeralds, and will inform you as to whether the stone has undergone any treatment of the kind a purchaser has the right to know about.

And one more piece of advice on the purchase of an emerald: whilst diamonds generously scintillate their fire in sizes below 1 carat, you should go for larger dimensions when acquiring a coloured gemstone. True, there are some lovely pieces of jewellery with small coloured gems to set decorative accents, but emeralds, like other coloured gemstones, do not really begin to show that beautiful glow below a certain size. How large 'your' emerald ends up will depend on your personal taste, and on your budget. Really large specimens of top quality are rare. This means that the price of a top-quality emerald may be higher than that of a diamond of the same weight. The fascination exuded by a fine emerald is simply unique.

Read More......

Saturday, May 16, 2009

AGATE

No gemstone is more creatively striped by Nature than agate, chalcedony quartz that forms in concentric layers in a wide variety of colours and textures. Each individual agate forms by filling a cavity in host rock. As a result, agate is often found as a round nodule, with concentric bands like the rings of a tree trunk. The bands sometimes look like eyes, fanciful scallops, or even a landscape with trees.

Agate was highly valued as a talisman or amulet in ancient times. It was said to quench thirst and protect against fever. Persian magicians used agate to divert storms. A famous collection of two to four thousand agate bowls which was accumulated by Mithridates, king of Pontus, shows the enthusiasm with which agate was regarded. Agate bowls were also popular in the Byzantine Empire. Collecting agate bowls became common among European royalty during the Renaissance and many museums in Europe, including the Louvre, have spectacular examples.

The mining of agate in the Nahe River valley in Germany, which was already documented in 1497, gave rise to the cutting-centre of Idar-Oberstein. Originally, the river was used to power the grinding-wheels. When the Nahe agate deposit had been exhausted, in the nineteenth century, Idar-Oberstein's cutters started to develop the agate deposits of Brazil, which sparked off exploration and the discovery of Brazil's rich deposits of amethyst, citrine, tourmaline, topaz, and other gemstones.

Although the small town of Idar-Oberstein is still known for the finest agate carving in the world, it now imports a huge range of other gem materials from around the world, which are then cut and carved in Germany and Asia. Cameo master carvers and modern lapidaries flourish along with rough-stone dealers who scour the world for the latest gem discoveries for export. And this entire industry sprang from that taste for agate bowls and ornaments during the Renaissance! Maybe agate is also a powerful talisman for success in international trade!

Read More......

Friday, May 15, 2009

GARNET

Aren't garnets those wonderful deep-red gemstones you often find in antique jewellery? Well yes, to a certain extent, a deep, warm red indeed being the colour most frequently found in garnets. Sadly, however, far too few people are aware that the world of the garnets is far more colourful than that. Spectacular finds, especially in Africa, have enhanced the traditional image of the garnet with a surprising number of hues - even if red does continue to be its principal colour. Thanks to their rich colour spectrum, garnets today can quite happily keep pace with changes of style and the colour trends of fashion. And thanks to the new finds, there is a reliable supply of them too. So in fact this gemstone group in particular is one which gives new impetus to the world of jewellery today.

By the term 'garnet', the specialist understands a group of more than ten different gemstones of similar chemical composition. It is true to say that red is the colour most often encountered, but the garnet also exists in various shades of green, a tender to intense yellow, a fiery orange and some fine earth-coloured nuances. The only colour it cannot offer is blue. Garnets are much sought-after and much worked gemstones - the more so because today it is not only the classical gemstone colours red and green which are so highly esteemed, but also the fine hues in between. Furthermore, the world of the garnets is also rich in rarities such as star garnets and stones whose colour changes depending on whether they are seen in daylight or artificial light.

And what else is there that distinguishes this gemstone group from the others? Well, first of all there is its good hardness of 7 to 7.5 on the Mohs scale. With a few minor exceptions it applies to all the members of the garnet group, and it is the reason for the excellent wearing qualities of these gemstones. Garnets are relatively insensitive and uncomplicated to work with. The only thing they really don't like is being knocked about or subjected to improper heat treatment. A further plus is their high refractive index, the cause of the garnet's great brilliance. The shape of the raw crystals is also interesting. Garnet means something like 'the grainy one', coming from the Latin 'granum', for grain. This makes reference not only to the typical roundish shape of the crystals, but also to the colour of the red garnet, which often puts one in mind of the seeds of a ripe pomegranate. In the Middle Ages, the red garnet was also called the 'carbuncle stone'. And even today, fantasy names like Arizona ruby, Arizona spinel, Montana ruby or New Mexico ruby are still rife in the trade.

The warm red of the garnet illuminated Noah's Ark
Garnets have been known to Man for thousands of years. Noah, it is said, used a garnet lantern to help him steer his ark through the dark night. Garnets are also found in jewellery from early Egyptian, Greek and Roman times. Many an early explorer and traveller liked to carry a garnet with him, for the garnet was popular as a talisman and protective stone, as it was believed to light up the night and protect its bearer from evil and disaster. Today, science has taught us that the garnet's proverbial luminosity comes from its high refractive index.

Not only do garnets have many colours; they also have many names: almandine, andradite, demantoid, grossularite, hessonite, pyrope, rhodolite, tsavorith, spessartine, and uvarovite, to quote but a few. But let us restrict ourselves to the most important and begin with the red garnets. First, there is the fiery red pyrope. Its spirited red, often with a slight brownish nuance, was a gemstone colour much in demand in the 18th and 19th centuries. Garnets from a find in the north-eastern part of the former kingdom of Bohemia - small stones of a wonderful hue - were world-famous at that time. In Europe, they were worked into jewellery a good deal, especially in the Victorian period. That genuine Bohemian garnet jewellery was traditionally set with a large number of small stones, which were close to one another like the seeds of a pomegranate, with their red sparkle. And today too, garnets are still found in former Czechoslovakia and set close together according to the old tradition, the attractiveness of classical garnet jewellery thus consisting mainly in the beauty of the gemstones.

The larger central stones of the typical 'rosettes' are also mostly of garnet, though they belong to a different category. For the 'almandines', named after Alabanda, an ancient city, have a chemical composition that differs somewhat from that of the pyrope. And why, one might ask, are they used as central stones? That's quite simple: because Nature has created the pyrope almost exclusively in small sizes, whilst allowing the almandine to grow in rather larger crystals.

A further garnet variety, also red, is the rhodolite. a mixed crystal of almandine and pyrope. This popular garnet is of a magnificent velvety red with a fine violet or raspberry-red undertone. Originally found in the USA, it now comes mainly from the gemstone mines in East Africa, India and Sri Lanka.

The colourful world of the garnets
The specialist world was amazed a few years ago by the fantastic find of a type of garnet which had been very scarce until then. At the Kunene River, on the border between Namibia and Angola, a deposit of radiant orange to red 'spessartites' was discovered. The spessartite was originally named after the site of a find made in Germany. Spessartites had led a quiet, shadowy existence as stones for gemstone lovers and collectors until that momentous discovery in Namibia. There were hardly any used in jewellery because they were so very rare. But this new find changed the gemstone world. Since then, its wealth has increased by the addition of this unusually fine, intensely radiant orange-red gemstone. Under the trade name 'mandarine-garnet', this wonderfully orange noble garnet became world-famous in no time at all. Unfortunately, the mine in the quiet hills of Namibia was only able to be exploited for a few years. The search for gemstones in the remote bush country began to involve too much effort and became too expensive. So fears grew that this highly precious gemstone, which had shot into the firmament of the gemmological world like a rocket, might only become available in rare individual cases from the stocks of a few cutting-centres. That is, until another deposit of the orange treasures was discovered, this time in Nigeria. Their colour and brilliance are so similar to those of the mandarin garnets from Namibia that only an experienced specialist can discern the subtle differences.

Now for the green garnets. Green garnets?! Is there really such a thing? Indeed there is! In fact, several green varieties are known. First there is 'grossularite', created by Nature in many fine tones of yellow, green and brown and esteemed for its many fine interim hues and earth colours. Here too, there was a spectacular find: in the final year of the 20th century, extensive grossularite deposits were discovered in Mali. These Mali garnets captivate us with their great brilliance. Even the brown, which is otherwise not terribly popular, seems vivid and natural, and goes particularly well with ethnologically inspired trends.

Probably the best known green garnet is the tsavorite or tsavolite, which also belongs to the grossularite group. Tiffany's in New York gave this name to the previous emerald-green stone which was discovered in 1967 by a British geologist, Campbell R. Bridges, in the north-east of Tanzania - after the place where the discovery was made, near the Tsavo National Park with its wealth of game. The green of the tsavorite runs from vivid and light to deep and velvety and, like all garnets, it has particularly good brilliance.

The star of green garnets is the rare demantoid, a gemstone for connoisseurs and gemstone lovers. Its brilliance is positively tremendous, even greater than that of the diamond. Russia's star jeweller Carl Fabergé loved the brilliant green garnet from the Urals more than anything else, and used it in his creations. Meanwhile, the demantoid is no longer quite as scarce in the gemstone trade, thanks to some new finds in Namibia. Demantoids from Namibia are of good colour and brilliance, but they lack one tiny feature: the so-called 'horse-tail inclusions'. These fine, bushy inclusions are the unmistakable, typical feature by which a Russian demantoid is recognised.

Gemstones for every fashion trend
Anyone who loves what is pure and natural and the warm, sun-bathed colours of late summer will be fired with enthusiasm by the colour spectrum of the garnet. Today, garnets mostly come from African countries, but also from India, Russia and Central and South America. The skilled hands of cutters the world over work them into many classical shapes, but also increasingly into modern, imaginative designer cuts. Garnets remain convincing with their natural, unadulterated beauty, the variety of their colours and their tremendous brilliance. Anyone acquiring garnet jewellery can be assured that the joy he or she derives from this beautiful gemstone gift from Nature will be long-lasting and undimmed.

Read More......

PERIDOT

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.

Read More......

Wednesday, May 13, 2009

TOURMALINE

Tourmalines are gems with an incomparable variety of colours. The reason, according to an old Egyptian legend, is that the tourmaline, on its long journey up from the centre of the Earth, passed over a rainbow. In doing so, it assumed all the colours of the rainbow. And that is why it is still referred to as the 'gemstone of the rainbow' today.

The name tourmaline comes from the Singhalese words 'tura mali'. In translation, this means something like 'stone with mixed colours', referring to the colour spectrum of this gemstone, which outdoes that of all other precious stones. There are tourmalines from red to green and from blue to yellow. They often have two or more colours. There are tourmalines which change their colour when the light changes from daylight to artificial light, and some show the light effect of a cat's eye. No two tourmalines are exactly alike. This gemstone has an endless number of faces, and for that reason it suits all moods. No wonder that magical powers have been attributed to it since ancient times. In particular, it is the gemstone of love and of friendship, and is said to render them firm and long-lasting.

Colours, names and nicknames
In order to understand this variety of colour, you will have to brush up your knowledge of gemmology a little: tourmalines are mixed crystals of aluminium boron silicate with a complex and changing composition. The mineral group is a fairly complex one. Even slight changes in the composition cause completely different colours. Crystals of only a single colour are fairly rare; indeed the same crystal will often display various colours and various nuances of those colours. And the trademark of this gemstone is not only its great wealth of colour, but also its marked dichroism. Depending on the angle from which you look at it, the colour may be different or more or less intense. It is always at its most intense when viewed looking toward the main axis, a fact to which the cutter must pay great attention when lining up the cut. This gemstone has excellent wearing qualities and is easy to look after, for all tourmalines have a good hardness of 7 to 7.5 on the Mohs scale. So the tourmaline is an interesting gemstone in many ways.

In the trade, the individual colour variants have their own names. For example, a tourmaline of an intense red is known as a 'rubellite', but only if it continues to display the same fine ruby red in artificial light as it did in daylight. If the colour changes when the light source does, the stone is called a pink or shocking pink tourmaline. In the language of the gemmologists, blue tourmalines are known as 'indigolites', yellowish-brown to dark brown ones as 'dravites' and black ones as 'schorl'. The last mentioned, mostly used for engravings and in esotericism, is said to have special powers with which people can be protected from harmful radiation.

One particularly popular variety is the green Tourmaline, known as a 'verdelite' in the trade. However, if its fine emerald-like green is caused by tiny traces of chrome, it is referred to as a 'chrome tourmaline'. The absolute highlight among the tourmalines is the 'Paraiba tourmaline', a gemstone of an intense blue to blue-green which was not discovered until 1987 in a mine in the Brazilian state of Paraiba. In good qualities, these gemstones are much sought-after treasures today. Since tourmalines from Malawi with a vivid yellow colour, known as 'canary tourmalines', came into the trade, the colour yellow, which was previously very scarce indeed, has been very well represented in the endless spectrum of colours boasted by the 'gemstone of the rainbow'.

Yet the tourmaline has even more names: stones with two colours are known as bicoloured tourmalines, and those with more than two as multicoloured tourmalines. Slices showing a cross-section of the tourmaline crystal are also very popular because they display, in a very small area, the whole of the incomparable colour variety of this gemstone. If the centre of the slice is red and the area around it green, the stone is given the nickname 'water melon'. On the other hand, if the crystal is almost colourless and black at the ends only, it is called a 'Mohrenkopf', (resembling a certain kind of cake popular in Germany).Tourmalines are found almost all over the world.

There are major deposits in Brazil, Sri Lanka and South and south-west Africa. Other finds have been made in Nigeria, Zimbabwe, Kenya, Tanzania, Mozambique, Madagascar, Pakistan and Afghanistan. Tourmalines are also found in the USA, mainly in California and Maine. Although there are plenty of gemstone deposits which contain tourmalines, good qualities and fine colours are not often discovered among them. For this reason, the price spectrum of the tourmaline is almost as broad as that of its colour.

The 'aschentrekker'
It is not only designers who love the tourmaline on account of its inspiring variety of colour. Scientists too are interested in it because of its astonishing physical qualities, for tourmalines can become electrically charged when they are heated and then allowed to cool. Then, they have a positive charge at one end and a negative one at the other. This is known as 'pyro-electricity', derived from the Greek word 'pyr', meaning fire. The gemstone also becomes charged under pressure, the polarity subsequently changing when the pressure is taken off. When the charge changes the tourmaline begins to oscillate, similar to a rock crystal but much more pronouncedly. The Dutch, who were the first to bring the tourmaline to Europe, were familiar with this effect a long time before it was able to be provided with a scientific explanation. They used a heated tourmaline to draw up the ash from their meerschaum pipes, and called the gemstone with the amazing powers an 'aschentrekker'.

In the fascinating world of gemstones, the tourmaline is very special. Its high availability and its glorious, incomparable colour spectrum make it one of our most popular gemstones - and apart from that, almost every tourmaline is unique.

Read More......