Diamond Mining in South Africa Contents
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ECONOMIC GEOGRAPHY: DIAMOND MINING IN SOUTH AFRICA CONTENTS Diamond mining has been SECTION D1 2 SECTION D5 43 taking place in South Africa What are diamonds? 3 Why diamond mining matters 44 for almost 150 years. But the What makes diamonds special? 4 Factors that favour and hinder diamond 45 mining in South Africa sector is far from reaching the Uses of diamonds 9 Safety and health 46 end of its life. SECTION D2 12 Environment 48 Where diamonds are found and mined 13 Diamond mining technology 52 South African diamond mining today 16 Synthetic diamonds 54 Quotes about diamonds 55 SECTION D3 18 Fun facts about diamonds 56 The diamond mining life cycle 19 SECTION D6 57 SECTION D4 26 Glossary of terms 58 People of diamonds 27 The big finds 31 Jobs in diamond mining 39 Brief history of diamond mining 40 in South Africa PAGE 1 MINING FOR SCHOOLS SECTION D1 People have always been attracted to beautiful objects. Diamonds have been treasured as gemstones since ancient times. Petra Diamonds PAGE 2 SECTION D1 WHAT ARE DIAMONDS? The word diamond comes Diamond is the crystallised form of pure carbon The funnel-shaped areas carved out by the (99.95% to 99.98%), the strongest mineral on magma eruptions are called kimberlite pipes, from the ancient Greek word earth, and one of the oldest substances known to named after the first formation discovered in adámas meaning invincible or man. The chemical formula of diamond is C which Kimberley, South Africa. is the chemical symbol for the element carbon. indestructible. Diamond ore, in its roughest form, doesn’t look The earth is estimated to be 4.5 billion years like the shiny nuggets on engagement rings. old. Most of the diamonds we find today started Diamonds must be sorted, cut and polished to THE to form between 1 billion and 3.3 billion years bring out their lustre. On average, 250 tonnes of EARTH’S CORE ago under intense heat (around 1,204°C) and ore must be mined in order to produce a single immense pressure, more than 150km below the carat gem quality polished diamond. earth’s surface in the mantle, an area consisting Rough diamonds come in all shapes and sizes, INNER CORE of volcanic magma. 1,600km colours and purities. They may be transparent, OUTER CORE Then, hundreds of millions of years ago, powerful translucent or opaque. The larger, whiter and 2,750km volcanic eruptions pushed the diamonds closer cleaner the diamond, the rarer it is. However, MANTLE to the earth’s surface. As the magma travelled premium prices can be commanded by coloured 2,800km up to the surface it ripped off pieces of the diamonds, which can be blue, pink, green, mantle taking the diamonds, embedded inside yellow, brown, orange, violet, black or grey. CRUST the crystallised host rocks, with it. 50-70km PAGE 3 SECTION D1 WHAT MAKES DIAMONDS SPECIAL? The diamond is known for its superlative physical qualities, A diamond most of which originate from www.forevermark.com/en/now-forever/ the strong molecular bonds is forever a-diamond-is-forever/frances-gerety/ between its atoms. In particular, Marketing has significantly affected the it has the highest hardness and image of diamonds as a valuable commodity. thermal conductivity of any Prior to the 1930s, diamond rings were bulk material. rarely given as engagement rings. Opals, rubies, sapphires and turquoise were much Diamonds were traded in India as early as the more popular to give as tokens of love. 4th century BC and were thought to possess Then De Beers changed the world diamond magical properties – just to gaze at a diamond market with a brilliant advertising campaign was considered strengthening. In the 1st century begun in the 1940s, causing demand for AD, the Roman naturalist Pliny said, “Diamond is diamonds to increase. The campaign was the most valuable, not only of precious stones, responsible for creating new markets in but of all things in this world.” Their usage in countries where no diamond tradition had engraving tools also dates to early human history. existed before. The popularity of diamonds has risen since The Diamond is forever ad campaign was the 19th century because of increased supply, created by the US advertising agency, NW Ayer, improved cutting and polishing techniques, in 1947. In 2000, Advertising Age magazine growth in the world economy, and innovative named this the slogan of the 20th century. advertising campaigns. PAGE 4 SECTION D1 WHAT MAKES DIAMONDS SPECIAL? CONTINUED The most familiar uses of diamonds today are THE as gemstones used for adornment, and as The commercial value of a diamond is industrial abrasives for cutting hard materials. determined by four characteristics known as The dispersion of white light into colours of FOUR Cs the ‘4 Cs’ – carat, colour, cut and clarity. the spectrum is the primary characteristic of gem diamonds. In the 20th century, experts in gemology developed methods of grading C1: Carat diamonds. Four characteristics, known The value of a diamond is partly determined by The following chart indicates the average informally as the ‘4 Cs’, are now commonly used its weight and the price per carat of diamond mm size per carat: as the basic descriptors of diamonds. rises proportionately with size. Approximate A carat is the international unit of measurement Carats diameter used to measure the weight of diamonds. One carat is the equivalent of 0.2 grams. 0.25 4.0mm In the diamond trade, fractions of a carat are referred to as points. One carat is divided into 0.5 5.2mm 100 points – so each point is 1/100th of a carat. A 10-point diamond weighs 1/10th of a carat, 1.00 6.5mm and a 50-point stone weighs one-half carat. More weight equals more money so many 1.5 7.4mm diamond cutters sacrifice brilliance to maximise carat weight and profit. But, weight does not always equal size or beauty. Poorly cut diamonds, 2 8.1mm even if they are big, can be dull and lifeless. PAGE 5 SECTION D1 WHAT MAKES DIAMONDS SPECIAL? CONTINUED C2: Colour Diamonds typically range from pale yellow to GIA colour grading scale colourless, but can also be brown, blue, green, SCALE D E F G H I J K L M N O P Q R S T U V W X Y Z orange, red, pink and black. Colour has a significant impact on the diamond’s appearance GIA GRADE as the presence of noticeable colour may reduce its ability to reflect light. Usually, the most Near Faint Very light Light Colourless valuable diamonds have little to no detectable colourless yellow yellow yellow colour. But, stones with colour called ‘fancy colours’ are very rare and are highly prized. The most common diamond colour is yellow and the Gemological Institute of America (GIA) Grading Scale for diamond colour is based on the amount of yellow that is visible. Each colour grade is based on a very small range. Petra Diamonds PAGE 6 SECTION D1 WHAT MAKES DIAMONDS SPECIAL? CONTINUED C3: Cut Regardless of the size of the diamond, cut is Very shallow Shallow Ideal Deep Very deep often considered the most important ‘C’, and is governed by man’s skill rather than by nature. The cut of a diamond is crucial to its ability to reflect light and has the greatest influence on its beauty. Cut refers to the evenness, symmetry and angle of a diamond’s facets. A master cutter cuts and Poor Good Excellent Poor Very poor angles to precise specifications so the diamond Appears dark Appears small optimally reflects the maximum amount of light through the top of the stone giving it sparkle and brilliance. If a diamond is cut too deep, light escapes out of the side and the centre will Diamond cut should not be appear dark, absorbing rather than reflecting light. A very shallow cut results in light escaping confused with diamond shape. through the bottom, causing the diamond to All diamond shapes are different and the unique characteristics of each diamond determines look like a dull piece of glass. the shape. Below are some of the most common diamond shapes viewed from above: In 1919, Marcel Tolkowsky, a mathematician and gemologist, developed the formula for cutting diamonds to achieve the most brilliance in a diamond. The round brilliant diamond cut has become an industry standard and is known as the Round Princess Emerald Asscher Marquise Oval Radiant Pear Heart Cushion ‘American Ideal Cut’ or the ‘Tolkowsky Brilliant’. PAGE 7 SECTION D1 WHAT MAKES DIAMONDS SPECIAL? CONTINUED C4: Clarity Because they are formed deep within the earth, under extreme heat and pressure; virtually all diamonds contain ‘birthmarks’; small imperfections inside the diamond (called inclusions), or on its surface (called blemishes). Flawless Internally Very very slightly included Clarity refers to the degree to which these flawless (VVS1 and VVS2) imperfections are present. Therefore, the fewer No inclusions or blemishes when No flaws on the surface or Minute inclusions that are difficult imperfections or inclusions within a stone, the viewed under 10X magnification by internally, only blemishes when for a skilled grader to see under rarer and the higher its value. a skilled grader viewed under 10X magnification 10X magnification and absolutely invisible to the naked eye The clarity scale was developed by the GIA to quantify these imperfections. All diamonds are systematically graded and plotted under 10X magnification. If a trained grader cannot see a clarity characteristic at 10X, it does not affect the clarity grade. Very slightly included Slightly included Included (VS1 and VS2) (SI1 and SI2) (I1, I2, and I3) Minor inclusions that range from Inclusions are easy (SI1) or very Inclusions may or may not be easily difficult (VS1) to somewhat easy (SI2) to see under 10X seen by the naked eye but are easy (VS2) to see under 10X magnification, but difficult with the obvious under 10X magnification magnification and almost naked eye impossible to see with the naked eye PAGE 8 SECTION D1 USES OF DIAMONDS People have always been bridal sector and are the traditional stone in engagement and wedding rings, representing attracted to beautiful, rare eternal love and commitment.