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Research paper for diamond
 

Research paper for diamond

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    Research paper for diamond Research paper for diamond Document Transcript

    • Table of Contents I. Introduction II. Diamond A. History of Diamonds  Early History  The Dark Ages  The Middle Ages  Recent Times B. Types of Diamonds 1. Pink Diamonds 2. White Diamonds 3. Champagne Diamonds 4. Pink Champagne Diamonds 5. Yellow Diamonds 6. Blue Diamonds 7. Green Diamonds C. Mining Diamonds 1). Pipe Mining 2). Alluvial Mining D. Diamond Cutting and Polishing 1). Diamond Cutting 2). Diamond Polishing III. Conclusion IV. Reference
    • I. Introduction Diamonds are decidedly one of the most highly valued and fascinating precious gems and considered by all people across the globe as nature's unique gift to mankind. It is interesting to know diamonds evolved - millions of years ago in pockets of carbon dioxide that existed deep beneath the Earth's crust. Tremendous heat and pressure combined to cause the carbon atoms to crystallize forming diamonds and the intermittent volcanic eruptions brought the diamonds up to the surface. Diamonds originate from two types of deposits - Primary deposits that consist of diamond-bearing pipes of a volcanic rock called Kimberlite. From deep inside the earth, these deposits were carried to the surface as molten rock called as magma. The secondary deposits, also referred to as alluvial, were formed as a result of erosion of material from primary deposits. They are said to contain diamonds that have traveled away from their original source. Even though world diamond production has tripled since 1980, diamonds continue to be a scarce resource. Geologists are using extensive methods in diamond exploration, including satellite surveys, reconnaissance sampling and drilling in the ground.It is the chemical and physical properties of this mineral that give it the superior cutting ability for industrial use. However, many people expect a diamond to be unbreakable. This is not true. A diamond's crystal structure has "hard" and "soft" directions. A blow of sufficient force, in a very exact direction, can crack, chip, split or even shatter a diamond.
    • II. DIAMONDS Diamonds have been a source of fascination for centuries. They are the hardest, the most imperishable, and the brilliant of all precious stones. The word "diamond" comes from the Greek word adamas, meaning "unconquerable". A diamond is a transparent gem made of carbon, one of the earth's most common elements. The formation of diamonds began very early in the earth's history, when the condensation of solid matter into a sphere caused the Centre of the planet to become subjected to incredible extremes of temperatures and pressure. It was these conditions that caused deposits of carbon to begin to crystallize deep in the earth. As the earth's surface cooled, volcanic activity forced streams of magna (liquid rock) to the surface, carrying with it the diamond crystals. Later, the diamond-bearing rock hardened, encasing the diamonds in vertical volcanic "pipes". But not all diamonds are found where they first came to the surface. Subsequent erosion of the topsoil over millions of years washed some of the diamonds into streams and rivers, and sometimes as far away as the sea. It is highly probable that they were first discovered in areas such as these, far away from their original location. The atomic structure of a diamond gives it the property of being the hardest substance known to man, natural or synthetic. The diamond is thousands of times harder than corundum, the next hardest substance from which rubies and sapphires are formed. Even after many years of constant wear, diamonds will preserve their sharp edges and corners when most other stones will have become worn and chipped.
    • A. History Of Diamonds From myths about valleys of diamonds protected by snakes, to the production of millions of carats in rough diamonds each year, the history of diamonds is one of mystical power, beauty and commercial expertise.  Early History The first recorded history of the diamond dates back some 3,000 years to India, where it is likely that diamonds were first valued for their ability to refract light. In those days, the diamond was used in two ways-for decorative purposes, and as a talisman to ward off evil or provide protection in battle.  The Dark Ages The diamond was also used for some time as medical aid. One anecdote, written during the Dark Ages by St Hildegarde, relates how a diamond held in the hand while making a sign of the cross would heal wounds and cure illnesses. Diamonds were also ingested in the hope of curing sickness. During the early Middle Ages, Pope Clement unsuccessfully used this treatment in a bid to aid his recovery.  The Middle Ages During the Middle Ages more attention was paid to the worth of diamonds, rather than the mystical powers surrounding them. Due to the heightened public awareness of the value of diamonds, mine owners perpetuated myths that diamonds were poisonous. This was to prevent the mineworkers swallowing the diamonds in an attempt to smuggle them out of the mines. The popularity of diamonds surged during the Middle Ages, with the discovery of many large and famous stones in India, such as the Koh-I-Noor and the Blue Hope. Today India maintains the foremost diamond polishing industry in the world.
    • As the Indian diamond supply dwindled, smaller finds occurred in Borneo and Brazil, but these were not sufficient to meet the ever-increasing demand for diamonds. The mid-nineteenth century discovery of diamonds near the Orange River in South Africa sparked the world's biggest diamond rush, and helped to satiate the world's increasing appetite for diamonds.  Recent Times During the mid-nineteenth century, diamonds were also being discovered in eastern Australia. However, it was not until late 1970's, after seven years of earnest searching, that Australia's alleged potential as a diamond producer was validated. On October 2nd 1979, geologists found the Argyle pipe near Lake Argyle: the richest diamond deposit in the world. Since then, Argyle has become the world's largest volume producer of diamonds, and alone is responsible for producing over a third of the world's diamonds every year.
    • B. Types of Diamonds 1. Pink Diamonds The pink diamond is the world's most rare and valuable diamond.The Argyle mine is the world's foremost source of unrivalled intense pink diamonds, producing 95% of the world's supply. However, an extremely small proportion of Argyle Diamonds production is Pink colour, in fact less than one tenth of 1% is classified Pink. The legend of Argyle pink diamond has grown over the past ten years. At the 1989 Christie's auction in New York a 3.14 carat Argyle pink sold for $1,510,000. Privately, Argyle has sold pink diamonds for up to $1 million a carat. For years the white diamond was considered the world's most beautiful diamond, until the discovery of the Argyle mine heralded the arrival of the Argyle pink diamond. Never before pink diamonds had displaying such intense shades of colourhad been seen. The natural colour diamonds have in fact been around as long as the classical whites but in much smaller quantities and never in great demand. The Argyle pink diamond comes in shades ranging from delicate pastel rose to robust raspberry and full-blooded purple-reds. The prices per carat are determined by the intensity of colour. Argyle selects only its most vibrant pink diamonds for polishing at its head office in Perth. There, the stones are polished in a wide range of cuts, such as round brilliant, marquise, oval and pear, to enhance their natural beauty. Polished pink diamonds are available in the same size ranges as traditional commercial sizes. Once a year, Argyle Diamonds issues a special release of outstanding pink diamonds that are sold by special bids in the international and invitation-only, Pink Diamond Tender.
    • 2. White Diamonds White diamonds are produced by mines all over the world in a wide variety of shapes and sizes.The white diamonds recovered from the Argyle mine are particularly brilliant and of high quality. White diamonds with secondary pink colour The Argyle mine also produces white diamonds with secondary pink colour that command a higher price per carat. In an effect similar to that described of pink champagne diamonds, the white diamond will display slight to bold flashes of pink when viewed from the top. A higher price is commanded for pink secondary colour depending on its depth and strength, because pink is one of the most rare colours found in diamonds. 3. Champagne Diamonds Champagne diamonds are naturally coloured diamonds that are produced in a wide range of colours from light straw to rich cognac. The 4C's of colour, cut, clarity and carat weight apply to coloured diamonds just as they do to colourless diamonds except the intensity of colour, not lack of it, plays a greater part in the valuation. Argyle Diamonds created the following scale specifically for champagne diamonds. The diamonds are graded on a C1-C7 colour scale. C1 and C2 represent light champagne, C3 and C4 medium champagne, and C5 and C6 dark champagne. The fancy cognac diamond is graded C7. 4. Pink Champagne Diamonds Attractive champagne diamonds with secondary pink colour are also available and command a higher price per carat than champagne diamonds. These stones display slight to bold flashes of pink in their fire.
    • Argyle Pink Champagne Diamonds are available in three ranges of shades, from light pink champagne to medium and dark pink champagne.As pink is one of the rarest colours found in diamonds, even secondary colours demand a higher price depending on depth and strength of colour. 5. Yellow Diamonds Fancy yellow diamonds come in a broad range of shades ranging from light yellow to a rich canary colour. A limited quantity of fancy yellow diamonds is recovered from the Argyle mine. 6. Blue Diamonds Fancy blue diamonds are available in a wide range of shades, from the blue of the sky to a more "steely" colour than sapphire. A Limited quantity of fancy blue diamonds are recovered from the Argyle mine. 7. Green Diamonds Fancy green diamonds are also available. Usually, penetration of the colour is not very deep and is often removed during the fashioning of the stone.A limited quantity of fancy green diamonds is recovered from the Argyle mine.
    • C. Mining Diamonds Of all the diamonds mined in the world each year, less than half are gem quality; the rest fall into two other main categories known as near-gem quality and industrial quality diamonds. Gem quality diamonds display a high standard of excellence in quality and are used in jewelry. The clarity of these diamonds ranges from flawless through to visible inclusions. Near-gem quality diamonds represent those stones of a quality between gems and industrial that in fact can be used as either depending on the individual stone. These stones have clarity grades ranging from visible inclusions through to industrial. Industrial quality diamonds are low quality or badly included stones and are suitable only for industrial use; for example, they are used in dentist's drills and earthmoving equipment. Diamonds are recovered by way of pipe or alluvial mining. 1). Pipe Mining Pipe mining refers to the extraction of diamonds from volcanic pipes. Typically, a very large area has to be covered. An average of 250 tonnes of ore must be mined in order to produce a one-carat gem quality polished diamond. In most countries, a diamond pipe mine is composed of kimberlite, or blue ground. Initially kimberlite is dug from the surface of the pipes in rough opencast mining. Once the surface deposits have been exhausted, shafts are sunk into the ground at the edge of the pipes, and tunnels are driven into the deeper parts of the pipes. After the diamond-bearing rock is brought to the surface, it is then transported to a screening plant where the diamonds are separated from the host rock.
    • 2). Alluvial Mining This process involves the extraction of diamonds from riverbeds or ocean beaches. Millions of years ago, at the time the diamond pipes were formed, some diamonds were weathered out of the pipes and carried great distances along rivers and even into oceans. In order to extract these diamonds from beaches, a wall is built to hold back the surf. Up to 25 metres of sand is bulldozed aside to reach the diamond-bearing level. Once reached, the diamond-bearing earth is removed and transported to screening plants. D. Diamond Cutting and Polishing The history of diamond cutting and polishing has its origins in India, where it was discovered a long time ago by Indian lapidaries that a diamond could be made to glisten simply by grinding another diamond against it. Nowadays the diamond and its powder play an important role in the cutting and polishing of diamonds. Over time modern machinery has replaced traditional diamond cutting tools.Diamond cutting and polishing requires anywhere from several hours to several months to complete. During this process, a diamond will lose on average half of its original weight. 1). Diamond Cutting As every diamond is different, a stone must first be carefully examined by the cutter and then marked for cutting. Of all the cuts, the most popular is the round brilliant because of its ability to give a stone the greatest possible brilliance and fire with the most minimal amount of weight loss. The following cutting and polishing procedures uses the round brilliant cut as an example.
    • The rough diamond is divided into two parts by sawing or cleaving. Most stones are sawn across the "grain" (visible evidence of the diamond's crystal structure) by a paper-thin metal disc coated with diamond dust revolving at high speed or by laser. The stones that are marked for cleaving are split along the grain by a single blow from a steel blade. After cleaving or sawing, the corners of the diamond are rounded off by a process known as bruting or girdling (only round brilliant cuts require this step). The stone is cemented into a "lathe", a holder that fits on a turning shaft. Another diamond is cemented to the end of a long rod held under the bruter's arm. As the lathe rotates, the two diamonds are brought together and grinded to shape. Diamond dust is produced from this action and is used in further sawing and faceting. The brilliant now has a girdle-a sort of rim at the widest part by which it is usually set. The size or position of the girdle should not change throughout the rest of the diamond cutting process. 2). Diamond Polishing The polishing of the diamond begins; one by one, facets will be ground on to the stone. A facet is the tiny plane or surface that traps the light and makes a diamond sparkle. Most diamond cuts have 58 facets.The facets are applied to the diamond on a "turntable", made of porous iron, which has been coated with diamond dust and oil. The diamond is set into a holder and held against the turntable as it revolves at a very high speed. A diamond has been cut well when its facets are clean, sharp, and symmetrical, and the proportions above and below the girdle are correct. A diamond is correctly proportioned when one-third of the total weight of the gem is above the girdle and two thirds below. A well-cut diamond will be fiery, brilliant and beautiful.
    • III. Conclusion A diamond is a transparent gem made of carbon, one of the earth's most common elements. The formation of diamonds began very early in the Earth's history, when the centre of the planet was subjected to incredible extremes of temperatures and pressure. Since the small stone that makes up the small four tons are industrial diamond. Diamonds are an ideal of mechanical parts that must resist wear and undergo a sudden temperature changes and that must not change size, create friction or rust. Diamond bearing are used in instruments for laboratoties. No friction is created when rubbing them together because of their hardness.Some machines turn at 90 000 revolutions a minute.No lubrications are needed even at this high speed to keep the bearing from wearing away.The round point on the diamond needs to resist being worn down.In turn, it does not wear out,it grooves on the record.The sound will stay true since the diamond does not rush. IV. Reference  http://www.webopedia.com/TERM/Diamond polishing.html  http://en.wikipedia.org/wiki/Diamond  http://diamondmining.net/  Jones, Kenneth L. Diamond Industry. New York: Harper and Row, 1989.  Payne, Wayne A., et al. Diamond: Issues for Today. Boston: Mosby Year Book, 1991. Project
    • In English Submitted by: Deci R. Vidallo IV- Aristotle Submitted to: Mrs. Cheryl D. Villanueva Teacher