Rock n Gem Magazine Issue 34
Published Winter 2005
Contents: Crystal Skulls, Living Space within Quartz, John Hamer Collection,
Coloured Gemstone Report, Fossil News, Ghosts, Phantoms & Veils, Minas Gerais,
Manufacturin Diamonds, Hardness< Burma Ruby Mines Co,
Pearls are in Vogue, Bismuth Minerals, Letters,
Shops Page, Rock 'n' Gem Shows Subscribe, Shows & Classifieds.
regular feature provided by R M Weare & Co
A new source of Amethyst is being produced from a deposit in Northern Cambodia. The stones being produced have a lavender hue, with pink undertones, and more brilliance than traditional sources from Brazil and Zambia. The deposit is located on the isolated Laos-Cambodia border and production is on a, as yet, small scale.
The recent Bangkok Gem and Jewellery Fair has highlighted the difficulty to source good quality cut gem material in Sapphire and Ruby. China's unequalled ability to cheaply cut material is forcing cutters in the established cutting centres of India and Thailand to compete by producing higher production rates at decreased costs, the result being a decrease in the cost of commercial goods and premiums on top quality material.
There has been a lot of interest in the new sources of pink sapphires and star rubies that have recently started production in Madagascar. Appraisal of these sources is currently being carried out by the International Coloured Gemstone Association and Madagascar's Service des Mines.
Pakistan's strong showing at the Bangkok Gem and Jewellery Show was aimed at increasing the industry knowledge of the vast range of gemstones that are available from within the country. Pakistan is already recognised as a source for Peridot, Ruby, Aquamarine, Tourmaline, Kunzite, and Lapis Lazuli, but it also has major sources of pink beryl's, diopside, epidote, garnets (of most varieties), moonstone, quartz, sphene, and zoisite.
A new source of sapphire in Malawi is producing good quality calibrated material. Reportedly similar in appearance to Thai Sapphire, production will increase when more of the extracted material is heat-treated. The United States company behind this, Columbia Gem House Inc, is to market the material with a range of selling tools to support the brand.
There have been many requests for cheaper pink stones, as pink sapphire prices continue to rise. Of particular interest to designers have been vivid pink Tourmalines and Rubelltites, particularly in cushion shapes. Morganite and Kunzite are still popular, but there has been a noted shift towards deeper colours with enquires for Bixbite and other unusual stones. Pink Cubic Zirconia sales are very strong. As predicted, emerald and peridot have been very popular over the summer period, especially in larger emerald cut stones. There has been increasing interest in opaque greens particularly in Jadeite and Chrysoprase Conna- Mara marble has been mentioned more than a few times as well! Paler coloured blue stones are in demand with requirements for Apatite and Zircon being of note.The lack of security in both Afghanistan and Pakistan is still keeping prices high. However, cost-conscious customers are showing reluctance to pay the higher price for the better material, and there has been an increasing acceptance for lower quality material. The popularity of lapis means that eventually the higher asking price will prevail.
Fine goods and large sizes in some categories are fetching much higher prices as a consequence of diminished supply. It is often difficult to find these stones even when money is not the limiting factor. Quite simply, the rough is not being found from which to cut the desired top grades, or large items, or both. As a result, many commonplace gemstones above a certain size leap in price.
Over the last decade there has been a large interest in the origins of crystal skulls; how they were made and what they were used for. But if we take a deeper look into the history of man, we can see traces of this mystery dating back to our ancestors. Albeit few priest or shamans that used them in the days of old their use is clearly evident.
The skull symbol represents many things, but its main aspects are protection, knowledge, life- force and death. These three qualities we can easily see when we look at what the skulls functions are during the life of a human. The skulls first and major priority is to protect the brain from physical damage, a very sensitive and
delicate organ for all its power, that once harmed can lead to complete disability as in a major accident or partial loss of control after a minor injury. The brain is where we house all our
collective knowledge in the form of memories. From an early age we learn from direct experience through interaction with life as well as from others experiences via reading and
verbal teachings. This knowledge has been passed down through generations and brought us to this modern age. Many ancient medical as well as shamanic belief systems thought that the life force of a human was stored in the brain. Finally the skull is only ever seen after someone has died and so represents death. This was always seen as change and the opening to new pathways and not as a bad omen. The belief in the powers of the skull are what led shamans and ancient orders of priests to use this symbol during rituals and ceremonies.
Some even created beautiful works of art such as the "Anna Mitchell Hedges" skull which is a life size skull carved completely out of quartz.
It is this skull that has caused such a stir over the recent years as science has been unable, through analysis and experiments, to label it in their parameters as the workmanship is so great they can't even date it or explain how it could have been made.
There are many theories that the skull was passed down through generations and each polished the skull a level further with fine clothes until it was complete. Being made out of quartz adds another dimension to the skull.
Quartz crystal has huge and almost limitless powers, it can store and transmit energy, it can be programmed to do specific tasks as well as purify, magnify and transmute energy. This makes the Crystal Skull a very powerful tool to use indeed, especially in the field of crystal healing and it's in this field that I wish to work with and look at in this talk. The hardest part is to find a crystal skull that resonates with you, there are many to be found but finding the right one can take time. Once you have a crystal skull it will have to be cleansed and dedicated to you. This is best done using flowing water over the skull as you channel the intent of any unwanted energies leaving the skull with the water. Then holding the skull in your left hand place the right hand over the skull and program it with the dedication to the good of all, to protect you in a sphere of bright white light, and lastly add the personnel line that you wish the crystal skull to work on for you. For example if you have a bad back you can ask the skull to help you heal your back.
Once this is complete, the skull will continue to emanate its healing energies and help to you until the programming is cleansed and you start again.
It is a good idea to make a shrine to place the skull on, maybe with a picture of you as well as other power items such as other crystals, herbs, incense, candles and bells. This will all help to create a more powerful energy to work with. Once this is all set up, all that's left to do is to find time each day to sit and meditate in front of the shrine, or to remove the skull and sit somewhere peaceful with it. Twenty to thirty minutes a day is a good time to spend in practice. While sitting start by looking deep into the crystal skulls eyes and allow yourself to relax; taking deep breaths and sighing the air out can help. Imagine yourself sat inside your crystal skull, feeling protected and relaxed, at ease with yourself and everyone else in your life. Let the healing energy of the crystal skull emana rough you. Sit with your back t and your hands cupped in your lap th the crystal skull cradled in them. With your eyes closed try to keep your internal focus on the crystal skull, remembering the sensations that you felt while looking deep into its eyes. If this is too strenuous, it is also possible to lay down with the crystal skull placed on the floor just above your head looking down your body; this also allows the healing energy of the skull to pass down into the body. This can be enhanced by placing quartz crystals in a circle around you; pointing inwards, at least 4 are needed but 6 or 8 are better.
This is an aerial view of the crystal healing grid to be used. The arrows represent the crystal points the tip of the crystal the arrow head. The eclipse represents the crystal skull and the text where you would lay down to heal. This would be a very powerful way to work with a crystal skull.Again for the best results its best to practice daily for 20 minutes and is much better than doing 2 hours once a week. As with all crystal practice it is a very personnel experience, you may find it helpful to keep a journal of your experiences as this will show you the progress you are making. Most of all remember to enjoy the experience, healing is gentle and fun, not all serious!
Lastly I would like to mention that there are many gemstone skulls available, and each gemstone type will have different healing properties according to its nature. The pictures show a few that are available, sugilite, smokey quartz and aqua aura.
A collection of fossil snippets from around the world, by S Cohen
From Bill Brysons 'A short history of nearly everything' about the rivalry between American dinosaur hunters Cope and Marsh. "They had much in common. Both were spoiled, driven, self-centred, quarrelsome, jealous, mistrustful and ever unhappy. Between them they changed the world of palaeontology. They began as friends and admirers even naming fossil species after other and spent a pleasant week together in 1868. However something then went wrong between them - nobody is quite sure what — and by the following year they had developed an enmity that would grow into consummate hatred over the next three decades. It is probably safe to say that no two people in the natural sciences have ever despised each other more. Marsh, the elder of the two by eight years, was a retiring and bookish fellow, with a trim beard and dapper manner, who spent little time in the field and was seldom very good at finding things when he was there. On a visit to the famous dinosaur fields of Como Bluff, Wyoming, he failed to notice the bones that were, in the words of one historian 'lying everywhere like logs'. But he had the means to buy anything he wanted. Although he came from a modest background, his uncle was the supremely rich and extraordinarily indulgent financier George Peabody. When Marsh showed an interest in natural history Peabody had a museum built for him atYale and provided funds sufficient for him to fill it with almost whatever took his fancy. Cope was born more directly into privilege - his father was a rich Philadelphia businessman - and was by far the more adventurous of the two. In the summer of 1876 in Montana, while George Armstrong Custer and his troops were being cut down at Little Big Horn, Cope was out hunting for bones nearby. When it was pointed out to him that this was probably not the most prudent time to be taking treasures from Indian lands, Cope thought for a minute and decided to press on anyway. He was having too good a season. At one point he ran into a party of suspicious Crow Indians but he managed to win them over by repeatedly taking out and replacing his false teeth.
For a decade or so Marsh and Cope's mutual dislike primarily took the form of quiet sniping, but in 1877 it erupted into grandiose dimensions. In that year a Colorado schoolteacher named Arthur Lakes found bones near Morrison while out hiking with a friend. Recognising the bones as coming from a `gigantic' saurian, Lakes thoughtfully dispatched some samples to both Marsh and Cope. A delighted Cope sent Lakes $100 for his trouble and asked him not to tell anyone of his discovery, especially Marsh. Confused, Lakes now asked Marsh to pass the bones on to Cope, Marsh did so, but it was an affront that he would never forget. It also marked the start of a war between the two that became increasingly bitter, underhand and often ridiculous. It sometimes stooped to one team's diggers throwing rocks at the others team. Cope was caught at one point prising open crates that belonged to Marsh. They insulted each other in print and poured scorn on each other's results. Seldom, perhaps never — has science been driven forward more swiftly and successfully by animosity. Over the next several years the two men between them increased the average number of known dinosaur species in America from nine to almost one hundred and fifty. Nearly every dinosaur that the average person can name — stegosaurus, brontosaurus, diplodocus, and triceratops — was found by one or the other of them. Unfortunately they worked in such reckless haste that they often failed to note that a new discovery was sometimes already known. Between them they managed to discover a species called Unitatheres anceps no fewer than twenty two times. It took years to sort out some of the classification messes they made. Some are not sorted out yet.
Of the two Cope's scientific legacy was much the more substantial. In a breathtakingly industrious career, he wrote fourteen hundred learned papers and described almost thirteen hundred new species of fossil (of all types, not just dinosaur) — more than double Marsh's output in both cases. Cope might have done ever more but unfortunately he went into a rather precipitous descent in his later years. Having inherited a fortune in 1875 he invested unwisely in silver and lost everything. He ended up living in a single room in a Philadelphia boarding house, surrounded by books, papers and bones. Marsh by contrast finished his days in a splendid mansion in New Haven. Cope died in 1897, Marsh two years later. In his final years, Cope developed one other interesting obsession. It became his earnest wish to be declared the type specimen for Homo sapiens — that is, to have his bones be the official set for the human race. Normally the type specimen of a species is the first set of bones found but since no first set of Homo sapiens bones exist there was a vacancy which Cope desired to fill.
Cope willed his bones to a learned society in Philadelphia. Unfortunately, after his bones were prepared and assembled it was found that they showed signs of incipient syphilis, hardly a feature one would wish to preserve in type specimen for one's own race. So Cope's petition and his bones were quietly shelved. There is still no type specimen for modern human".
The last curator of Yale's Peabody museum started by Marsh was Professor John Ostram who died in July. He sparked fierce debate by demonstrating that dinosaurs bore more affinities with birds than with lizards and suggested that birds were direct descendants of dinosaurs. When fossil hunting in Mongolia in 1984 he found a small carnivorous dinosaur with large sickle shaped claws and powerful hind legs, which he named Deinonychus, meaning terrible claw. He described the beast as a raptor that hunted in packs and killed its prey by leaping, killing and slashing with its claws. This behaviour he deduced indicated an agile animal capable of considerable bursts of speed, suggesting it had a high metabolic rate, and was probably warm blooded. At the time this was considered new and revolutionary by some and heresy by many more. In the 1970's he compared dinosaurs to Archaeopteryx, the oldest known bird (like) fossil, noting 200 shared anatomical features between carnivorous dinosaurs (therapods) and birds — including a wishbone, swivelling wrists and three forward pointing toes. He suggested in 1973 that dinosaurs might have evolved feathers for insulation, not flight, and that birds evolved from feathered dinosaurs. By now he had upset orthodox ornithologists as well as palaeontologists'.They pointed out that no fossil links between reptile like dinosaurs and birds had ever existed. Then in the 1990's well preserved feathered dinosaurs were found in Liaoming Province, China. The most impressive was Protoarchaeopteryx, a turkey sized dinosaur with long arms and legs and symmetrical quilled feathers. Feathers have to be asymmetrical to facilitate flight so this discovery probably confirmed Ostrams theory that feathers evolved for the purpose of insulation. Dinosaur research was out of fashion when Ostram began his work. His revolutionary theories did much to encourage a new interest in the field and consequently he taught many of today's leading dinosaur specialists. His theories were also responsible for the depiction of the behaviour of the nasty, mischievous velociraptors in Jurassic Park! More Birdy Dino Stuff. A fossilised dinosaur pelvis containing 2 unlaid eggs was found recently in China. Scientists say the dinosaurs reproductive system functioned more like a birds than a reptiles and it laid successive pairs of eggs, rather than a large clutch all at once. A new study suggests the hollow spaces between big bones in therapod dinosaurs may contain air sacs similar to those in birds. They allow birds to extract oxygen while breathing air out as well as in, facilitating a high metabolic rate and extended bursts of activity. Until now Palaeontologists have been sceptical of whether dinosaur anatomy would be sophisticated enough to function as modern bird lungs. From Francis Gill, Fossil Cavern, Isle of Wight.
A dromesaur dinosaur with a beak like snout, feathers and wing like limbs has been found in Patagonia, Argentina. Until now dromesaurs have only been found in Asia and North America and it was thought they didn't colonise the southern hemisphere before the ancient continents of Lawrasia and Gondwana separated about 160 million years ago. This dromesaur is 90 million years old from Richard Allinson of the Fossil Store, Preston.
Headline in the Telegraph: "Biplane dinosaurs beat Wright Brothers by 125 million years", - such are the claims of a new study of microraptor, a small dinosaur found in Liaoming Province, China (where else?) two years ago. The 120 million year old creature weighed about 1 kilo, was under a metre long, with a bony tail and flight feathers on its front and back limbs. Because dinosaur limbs cannot be splayed sideways the creature could not have extended its rear limbs to form a wing directly behind its front wings, like a dragonfly does. More likely and more aerodynamically stable would have been a rear wing held lower than the front wing, similar to the configuration of an early biplane. A computer analysis has microraptor launching itself from a high branch and falling head first until it reached a speed that created sufficient lift for it to swoop upwards and land in the branches of another tree, all without having to flap its wings. The study concludes "it is intriguing to contemplate that perhaps avian flight, like aircraft evolution went through a biplane stage before a monoplane system was introduced.
Roy Shepherd has been a fossil enthusiast since the age of 4. Two years ago he created discoveringfossils.co.uk which has descriptions of fossil sites and information about collecting, preparation and identification of fossils. It has been endorsed and recommended by English Nature, especially for its advice about responsible collecting. It gets about 4000 hits a week. For a more extensive list of over 150 fossil sites, check uk.fossils.co.uk this gets about 11000 hits a week.
A prolific fauna of carboniferous trees and ferns has been exposed in the village of Brymbo (pronounced Brumbo) near Wrexham. Following the demolition of its old steelworks. Plans are afoot to create a geology trail, a rockface display showing fossil trees rising from their coal seam base and a collecting area where children can search through 200 tons of fossil rich rock.
In August' National Geographic the top 7
dinosaur sites were listed as
1, Liaoming Province, China (unique preservation, feathered dinosaurs, all sorts of weird new stuff, 120 million years old)
2, Bahariya Oasis, Egypt (huge old dinosaurs roaming steamy mangrove swamps, 97 million years old)
3, Alberta, Canada (biggest species diversity of any site and vast herds of horned and duck billed dinosaurs, 70 million years old)
4, San Juan Province, Argentina (the dawn of the dinosaurs, some of the oldest known remains, 230 million years old)
5, Ukhaa Tolgod , Mongolia (prolific, fabulous preservation, 80 million years old)
6, Isle of Wight, UK (where some of the first discoveries were made and still capable of yielding a surprise, 110 million years old)
7, Western United States (lots and lots of big stuff, 150 million years old)
Ghosts, Phantoms & Veils
I have not joined an occult or become a ghost buster, these are actually terms used for features within quartz crystals.
Substantial additional crystals can often be seen within a single quartz crystal, usually emanating from the base. These separate crystals denote a change in the previous level of growth; these changes are nearly always in line with the true apex of the crystal. There is a strong tendency to cut and polish these giving an artificial crystal, usually to enhance the attractiveness and therefore the commercial value. Ghost crystals can be partial and offset with only part of a crystal visible. Fortunately, crystals that have been cut always have a bevel around the base.
More substantial layers within a quartz crystal can often give an indication of the prior existence of a previous crystal form. They provide seemingly substantial divisions and also act as attraction for other inclusions; they could also have electrostatic implications. The crystal divisions are reasonably substantial and can also contain bubbles of gas or fluid, either singly or together. Often phantoms will act as catalysts for the further attraction of small particles of Iron or Calcium. Readers should also see the article on Colloidal particles.
Phantoms can often be clearly seen as fine green layers and therefore they are most probably of Chlorite. When included layers are quite substantial, they lead on to what are referred to as rows of "library shelves.
These are often delineated within a crystal as slightly opaque fine sheets; these can be flat or corrugated. Veils are not always obviously associated with the quartz crystals structure but should not be confused with fractures. They can be found together with inclusions of Rutile, when needles seem to grow either through the veils or even emanate from them. They range from insubstantial impressions, to more substantial veils and usually denote a change in the speed of crystal growth. ". Other more substantial inclusions such as dendrites and floating crystals, of which there are many, will also have to wait for a later article.
Living Space Within Quartz
When looking at quartz inclusions under the microscope, I was intrigued by certain structures I could see. I thought about the general shape of these very small inclusions and started to think, "the structures somehow looked familiar".
I remembered then that I had seen similar looking microscopic structures before, I realised that they had also looked similar to the possible bacteria photographed inside a meteorite from Mars. Yes, I did feel for a moment this was a crazy idea, but then I remembered two other observations that seemed to add weight to my thinking.
Firstly, I remembered that when looking at some gold depOsits in South Africa, it was reported that microbes could have played a part in concentrating some of the Gold. Secondly, I recalled the discovery of volcanic chimneys called black smokers, deep down on the sea floor. These volcanic vents are found on underwater hot fissures located on the margins of tectonic plates near to spreading ridges. The microbes discovered there were actually flourishing in extreme environments. Also we already know that bacteria can live in very hot conditions, at very high atmospheric pressures and they can even live on sulphur. Bacteria it is also reported can be found deep within the Earths crust; perhaps my line of thinking was not as far fetched as I first thought!
I asked myself the simple question,"Why are these inclusions all the same diameter? Even large clumps, appear to be composed of minute individual worm like concentrations of these structural elements. If mineral particles exist; surely they should be of random diameters? If you can, I would urge you to take a closer look at the fine inclusions found in some quartz.Yes, the notion may seem a little far-fetched, but to help us it is reported that at one stage quartz must exist as non-solid gel. For a microbe, such a non-crystalline soup, rich in the essential mineral elements, would provide an ideal breeding ground!
The John Homer Collection
"For the time I was here I was suspended in wonder" Museum visitor book July 2005
The late John Hamer of Ingleton, a potholer and mineral collector, who lived to be over 90 years of age, collected during his long life one of the most superb and extensive mineral collections known in the North of England.
The total collection exceeds 2000 specimens and includes beautiful ruby crystals from Myanmar and spectacular tourmaline crystals embedded in quartz from Brazil. But perhaps the most important specimens are those collected from long disused mines in the Lake District, where mineral collecting is now banned, and other regions of northern England. John Hamer rescued superb irreplaceable specimens from these sites, collecting them before deterioration from exposure to the elements occurred.
The entire collectionwas saved and removed to the Museum where it has been catalogued. This invaluable reference collection is available for research and enjoyment by both geologists and those who are just fascinated by beautiful minerals.
A spectacular display from the collection together with a complete catalogue, original note books, display charts and a map locating mine sites are featured as a new permanent display at Kendal Museum.
A crystal or crystalline material is a mineral that is made up of atoms that are arranged in an orderly, regularly repeating pattern.
Most healing stones are crystalline.
Some people believe that crystals have the metaphysical power of healing, by using certain crystal methods. It is said that crystal healing can help a number of physical problems. However this relies on the innate powers of the healing crystals.
Crystals and healing
Crystals were first used in the legendary lost city Atlantis, through the ancient Mayan and Hebrew civilizations, and including Far Eastern and Native American cultures, crystals and gemstones have been used both in spiritual rituals and as aids to physical healing. They became very important to the people of that civilization who believed in their capacity to store and amplify any power source fed into them- physical, mental, emotional, or spiritual.
However, today the practice of using stones and crystals continues. Not only with the aboriginal shamans of Australia who use stones to commune with the spirits, but with ordinary people across the world who claim extraordinary results!
Practitioners of modern-day crystal therapy believe that the stones' ability to work as conductors allow them to focus energy via a person's thoughts to stimulate healing — both physical and non-physical. But no one seems to know exactly how crystals work!
How to use the crystals?
"Your commitment to the crystal is part of the healing process". Crystals are used in meditation and spiritual ceremonies, laid on the body during types of massage or bodywork, when a person is resting, or placed in drinking or bathing waters. It is claimed that an odd number of facets on the stone aid in healing, while an even number of facets create the best energizers.
Red, yellow, and orange stones are said to produce energy, clear and aquamarine stones are healers, and lavender and blue-violet stones create calming effect.
The length of time to obtain the effects desired is depended upon the quality of the crystal (size, colour, and energy charge), location of wear, duration, and the crystals appropriateness to your healing issue. Below is a picture of different gemstones that are commonly used as healers, and a list of five known crystals and their reputed benefits...
Amethyst The "Master healing crystal" purifies and transmutes negativity. Amethyst provides protection and balance during transition periods. It reduces anger, impatience and nightmares.
Rose Quartz The "love stone". It is a master healer and it enhances meditation and healing by harmonizing and balancing energy fluctuations. It's good to wear in a chaotic or crisis situation. It is the stone of gentle love bringing peace and calm to relationships. The "woman's stone". Red coral encourages a passionate energy, and stimulates and strengthens the female reproductive organs through tissue regeneration. It's not to be used with high blood pressure. It's also good for your blood, heart, and bone regeneration.
Amber A -`:gentle stone". A fossilised tree resin that is very soothing and calming to the nerves. It allows the body to heal itself by absorbing and transmuting negative energy to positive energy. It also transmutes the energy of physical vitality towards the activation of unconditional love.
The `grief stone". Apache tears (transparent obsidian) allows for tears to be shed, stimulating emotional spontaneity and the release of barriers that prevent you from experiencing deep sorrow.
Note that it's not a total guarantee that crystals are healers; it all depends on belief!
Welcome to this Issue's selection of articles from the HND second year students at the University of Central England, in Birmingham's Jewellery Quarter.
We have articles from 6 students: Stuart Galbraith, Kate Slovak, Sonny Kearney, Dan Rumbol, Sophie Lesetedi and, our international visitor from China, Gong Zhen. I'm sure you will enjoy the insight of these young people into the world of Gemmology. For any further information regarding either this course or any of the Gemmology or Diamond Grading courses run at the University, please see my advertisement for contact information. Happy Gemmology!
AN ABUNDANT LAND OF GEMSTONES & MINERALS
Brazil produces the greatest variety of gems & semi-precious stones in the world, including diamonds, emeralds, quartzes, alexandrite, chrysoberyls & topaz.
Mining is very much part of the Brazilian culture and a way of life. It is fascinating to know that about 40% of Brazilian territory has crystal rocks which may have pegmatite pipes, the gem and mineral bearing deposits.
Some of the most special gemstones in the world have come from a region near the city of Belo Horizonte in the state of Minas Gerais (the name literally means general mines) an area that produces 80% of Brazil's precious gems and minerals.
Minas Gerais was formed mainly by colonists who searched for veins of gold and gemstones and set up mining settlements in the area.The gold and diamond rushes helped boost the occupation in the state and led to the foundation of several new towns and villages. In the 17th century Mariana became the first capital; but later this moved to Vila Rica (meaning rich village), which became the biggest city in Brazil. As the gold mines were exhausted over the 19th century, the city lost its importance. It was renamed Ouro Preto (black gold) and remained the capital until the construction of the all-new, planned city of Belo Horizonte at the turn of the 20th century.
As Minas Gerais probably has the greatest number of pegmatite pipes in the world, it has in turn got a great number of mines that have produced many of the greatest gem crystal specimens of tourmaline, aquamarine and kunzite. These mines include the primary (pegmatite's) deposits at Cruzeiro, Jonas, and Corrego do Urucum, and the secondary (alluvial) deposits at Barra de Salinas, and the Pioneer mine in the Tres Barros region near Marambaia. In the Itabera region of the state there are a couple of emerald bearing mines- Belmont and Piteiras, both alluvial and underground. Much of the mining is done underneath the emerald bearing rock, allowing gravity to do much of the work. The emeralds are hosted in a magnesium rich biotite called phlogopite; referred to as "black wall zones". At the base of Mount Ibituruma sits Governador Valadares. Here there is not only a national centre, recognised for both the cutting and trading of coloured gemstones, but also the Navigator mine, known for producing mica and feldspar. In 2000, a pocket was discovered containing a variety of minerals. Since then four more pockets have been found, which has made this mine famous for blue-green tourmaline. Gem deposits are generally found at random in Brazil as there has been limited research into the prospective gem laden gravels and so discovery of large deposits has almost always been accidental. Consequently Minas Gerais, and Brazil in general, continues to have an immense gemstone potential, particularly as there are lots of pegmatite pipes still not mined.
Therefore the biggest deposit ever could be waiting to be discovered and who knows, possibly a new gemstone that will rock the gemmology world, just like tanzanite did in the 60's. The future is also positive now that the country offers a favourable atmosphere for the entry of efficient and well-organised gem mining companies, due to deregulations by the government and advancements in geological and geophysical prospecting.
Stuart Galbraith DGA
Manufacturing of Diamonds
Manufacturing is the correct terminology for describing the fashioning of a rough diamond crystal.
A small amount of science is required in fashioning a diamond crystal to achieve its true brilliance and fire. Total internal reflection (T.I.R) is the result gained by cutting a crystal to diamond's ideal proportions.
There are four stages that are used to fashion diamond crystals: 1. Design & Marking 2. Dividing 3. Shaping 4. Faceting & Polishing These Four Stages are taken into account when trying to achieve maximum profit and yield from the rough crystal.
Design & Marking
A designer will inspect a diamond crystal and mark it where he/she thinks where it should be divided to achieve max profit and yield. Various aspects such as shape of crystal, colour, inclusions and weight have to be considered for by the designer.
Once the crystal has been marked using a permanent marker the crystal has to be divided. It can be divided in a number of ways. The most common are: Cleaving, Sawing and Laser Cutting.
A process called bruting is used to achieve the initial rough shape required from the crystal. It is done by abrading one diamond with another. A type of lathe is used to bring the crystals together in a back and forth motion. Before machinery this process was done by hand but didn't achieve good circular results.
Faceting & polishing Faceting
and polishing is the final and most complex stage. 57 facets are applied or 58 (if a culet is present). Very little equipment is needed but in depth knowledge and experience is required. A Scaife, Tang and Dop are the three main pieces of equipment used in diamond faceting and polishing. A scaife is made of cast iron and is a flat circular disc with one or two spindles. Most are 30-40cm in diameter and around 2cm thick . the spindles are belt driven by a motor at approximately 2900rpm. The tang and dop are what holds the diamond onto the scaife. The tang has a tripod design, which holds the dop that holds the diamond. Modern dops are usually adjustable so that the diamond can be held with ease.
The polishing of a round brilliant
There are two stages in polishing a brilliant cut stone. The first is done by a crossworker whose job it is to apply the first 18 facets. The crossworker gets the basic shape of the stone. He/she applies the table facet, four bezels and four corners to the crown of the stone. Four facets are placed to the pavilion. A culet may be applied at this stage. The stone is then passed to a brillianteer who applies 40 facets to the stone. If cut to diamonds ideal proportions the stone will exhibit balanced amounts of brilliance and fore.