Gold

By Minik Rosing

Gold is precious, which means it exists as separate metal in the nature. Almost all other metals have to be won from minerals, which are a chemical combination with other elements. The winning of other metals therefore needs advanced technology and large amounts of energy. Gold on the contrary is found as metallic grains of gold in the rocks in the earth’s crust. When the mountains disintegrate and crumble due to the influence of the weather, the grains of gold are separated from the other minerals and are transported with brooks and rivers towards the sea.

Gold is very heavy, 6 – 7 times heavier than most other minerals. Gold is deposited on the bottom of the river beds, while the lighter minerals whirl away in the stream. In this way gold is concentrated in the sand and gravel of the river beds. It is here that mankind for the first time saw the gold and marvelled at its beautiful sun-yellow colour and the peculiar metallic characteristics. In the same way as the rivers themselves have concentrated the gold, man can separate the gold from the rest of the sediment by whirling it around in a homemade eddy in a hollow. The current will hurl the lighter minerals out over the edges of the hollow, while the heavier gold will stay on board. This is what is called “gold washing”. As long as man has been able to quench his thirst for gold by wandering around rivers and brooks and wash the gold out of sediments, the winning of gold was quite strenuous and more or less caused no harm to nature.

Some rocks contain more gold than others, but even rocks very rich in gold seldom contain more than a few grams per ton. In districts where the rivers have contained remarkable amounts of gold, it is obvious to believe that the mountains, which have been washed by these rivers, must have contained extraordinary concentrations of gold.

It has often been noticed that some parts of a river system has contained extraordinary large amounts of gold, while other parts of the system has been poor in gold. By studying where in the river system the gold is, it has been possible to “nose out” the source of the gold – the gold vein. On these places people then started to crush the rocks to win the gold – and then suddenly the gold winning changed from being a difficult but harmless occupation to become more or less destructive of the surrounding environment.

When washing gold, it is only possible to catch the gold grains, while the gold dust is thrown out with the water. As the larger part of the gold consists of gold dust, people have worked on finding methods to collect the gold dust too. Very early it was known that mercury in an almost magical way can dissolve gold. By rolling a drop of mercury in the gold wash bucket, it is possible to catch all the fine gold dust, which is either invisible or too fine to catch. Gold is now part of the combination gold-amalgam. The gold is now separated from the mercury by heating the amalgam. The mercury evaporates and leaves a small ball of pure gold. As mercury is very expensive, it has often been tried to collect the evaporated mercury in a retort, but in any case gold winning leads inevitably to emission of mercury to nature. Gold winning is no longer innocent and the forests no longer so green. A great part of the low-technology gold winning in the less developed countries is still carried out with mercury, and thus the gold diggers and the surrounding nature is suffering immensely. Mercury is one of the most problematic environmental poisons you can think of, because it is extremely poisonous for all organisms, and because it is an element, which cannot be biodegraded in the nature.

Mercury is expensive and therefore in the industrialized gold winning, people have tried to find cheaper remedies for dissolve gold. It has been found out that cyan – the renowned poisonous substance, which everybody knows from crime novels, smells of bitter almonds – can be used to dissolve gold. As cyan dissolved in water is much cheaper and easier to handle than mercury, it is possible to win large amounts of gold from crusted rocks by using this material. And it is now-a-days the favourite method by modern gold mining. Cyan is extremely poisonous, but it is very quickly biodegraded in the nature, and therefore it does not have very big environmental consequences if used with consideration to nature.

Rocks containing large amounts of gold notoriously often contain large amounts of the element arsenic – the active element of the crime novel genre’s other favourite poison, arsenic. When you dig and crush large mounts of gold ore to win the gold by using cyan, giant loads of fine-crushed arsenic rock flour will remain. Beyond the nature destructive in removing whole mountains in order to get hold of the gold ore, one of the large environmental problems in modern gold mining is the reclaiming of the poisonous sediment, which remains after the winning of the gold.

Like gold diamond is an element – namely carbon. Carbon is mostly known as coal used for the grill or as lead in pencils. Deep down under the continents the pressure in the earth is extremely high, and here carbon is found in a more compact form, namely diamond. Diamond is the hardest material known, and as diamonds like gold are heavier than most other minerals, they are concentrated in sand and gravel of the rivers and can be found by washing the lighter minerals away. As long as diamonds were found more or less by chance in the rivers, nature was not harmed.

Diamonds are water-repellent, which can be used in the process of sorting them out from the normal mineral grains in the sediment. As diamonds do not get wet, they will stick to greasy surfaces, to which wet stones cannot stick. This experience has made it possible to process large amounts of sediment and win the diamonds in a so-called “grease belt”. To-day in some areas it pays to win the diamonds from finds containing only 0.1 carat per 100 ton sediment. It goes without saying that enormous amounts of sediment has to be dug out to find diamonds enough for even a modest royal crown. Beyond the social and political disasters following the mining of diamonds in many of the less developed countries, it is obvious that massive destruction of the nature will take place, when enormous amounts of earth are dug out to find very few but costly diamonds.

Gold and precious stones have some seldom qualities, which we connect to aesthetic qualities. Some of our desire for these materials is surely combined with their function as symbols of wealth and power, but on the other hand there are not many other, seldom materials, which we do strive for with the same enthusiasm as for gold and diamonds.

It would be to pull the wool over ones eyes to think that gold and precious stones can be mined without environmental consequences. They are so seldom that enormous amounts of rock material have to be processed in connection with the mining. That demands lots of energy, results in destruction of land and perhaps to emission of damaging elements contained in the ore, or damaging elements used in the process of mining.

Part of the purpose of giving a precious piece of jewellery as a present is to express one’s wish to do a great and irrational effort with the sole purpose to make the recipient happy. Therefore the value of jewellery is mainly set according to how difficult it is to get hold of the raw materials and how much work the jeweller has put into producing the piece.

On the other hand it is very important to get hold of the needed raw materials in a less radical way in order to protect both nature and the people working in the industry. It is this decision only to use materials, which by document can be proved to have been mined in the most careful way that are the hallmarks of the Fair Trade Concept within the jewellery trade.

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