Sunday, October 17, 2010

History of Gold

Gold history
Gold is one of the ten elements of ancient times. The oldest findings date back to the 5th millennium before Christ. The Egyptian pharaohs regarded gold as a divine metal. They considered themselves to be descendants of the Sun God. Gold was a means of achieving immortality, for which reason a deceased pharaoh was wrapped in gold, i.e. the burial chamber was filled with items made from gold and silver. When Tutankhamun’s grave was excavated in 1922, the researchers found the pharaoh’s mummy surrounded by three sarcophaguses, while the inside was made of solid gold and weighed more than 108 kg. The burial chamber featured chariots made from white gold, golden daybeds, statues and Tutankhamun’s throne, which was fully plated in gold foil.
The Roman Empire was to some extent established on the basis of stolen gold and silver. Within three hundred years, the Romans managed to attain control of all known mines and deposits of the then known world. Gold and silver were a solid currency, and golden adornments and statues everywhere paid witness to the wealth of Roman life. The Romans already knew a cleaning method by smelting with lead, common salt or chalk.
Gold was also one of the driving forces for Christopher Columbus to search for a new sea route to India. In the 16th century, the Spanish conqueror Hernández Cortés landed near what is today Vera Cruz and subjugated the people of the Aztecs. The king of the Aztecs, Montezuma, welcomed the Spanish with gold presents, but this, of course, only incited the greed of the Spanish all the more. They strung the king along with lies and then murdered him and his entourage at a convenient time. They also destroyed the Aztec capital and were responsible for a terrible massacre of the population. The entire gold of the Aztecs was taken to Spain on ships. This story has been repeated in the line of history in many other variations, whether it is the murder of Inca king Atahualpa by the Spanish conqueror Pizarro in 1532, or the murder of thousands of Indians by Western settlers in the United States in the 19th century.
In the Middle Ages, alchemists tried to use transmutation from other substances to artificially create gold, which was never a success. They regarded cinnabar and mercury for a preliminary stage of the so-called “philosopher’s stone”. The idea was that this was a magic substance, which had the property of making gold from worthless metals. The alchemistic symbol of the circle initially represented the solar disk.
Properties:
Gold is a precious metal which shines in a golden yellow and has a high level of density. It is the most flexible of all metals, 1g of gold can be extended to a wire with a length of 3 km. The metal can be rolled out to gold leaf, which has a thickness of approx. 1 micrometre. The yellow gold leaf appears blue-green when glancing over it. Gold can be alloyed with other metals; when doing so with mercury, amalgam is created. In addition to silver and copper, gold is one of the three best conductors of heat and electrical power. Gold is a very precious and corrosion-resistant metal, which is not affected by air, water or acids. Only chlorine water or aqua regia can dissolve gold.
Deposits:
Gold is a rare element and ranks above platinum 75th as regards element frequency. In the earth’s crust, up to a depth of 16 km, gold can be found with a share of 4.1mg/t in the rock, iron meteorites have an average share of 1.8g/t and seawater has 1-2 micrograms of gold per cubic metre of water. In nature is mainly occurs as native gold in elementary form but is nearly always contaminated with silver and other metals, such as copper, bismuth and mercury. Gold with a content of more than 30% of silver is called electrum. Grains, lumps or “nuggets” are found in river sands which can be found by “gold panning”.
The biggest nugget of the world so far was found in 1931 near Kalgoorlie/western Australia. It is the “Golden Eagle” with a length of 67.4 cm and width of 29.2cm! It has a proud weight of 71.177 kg.
The nuggets are originally from quartz veins which were washed away by water. Due to its high density, the washed-out grains fall to the ground of the river sediment as “soaps”. Some minerals, such as quartz or pyrite, have a minor contamination with gold.
The biggest gold deposits in the world are on Witwatersrand in the Republic of South Africa. The gold content is up to 45g/t of quartz rock. Other significant deposits are in Mother Lode/California, in Cripple Creek/Colorado, in Alaska, in Canada, in the Urals, in Ghana or in Zimbabwe. The biggest lump of gold found to date had a weight of 71 kg and was brought to light in Australia in Kalgoorlie. The most important deposits in Europe are in Transylvania. In Germany the rare metal is recovered with other precious metals from copper pyrite and galena, while the gold content per tonne of ore is approximately one gram. The global reserves are estimated to be approx. 60,000 tonnes. The gold deposits in the world seas, however, make up several tonnes, but their extraction is currently not profitable.
Gold extraction:
The oldest method of extracting gold is gold panning. With this method, river sands are slurried in an industrial plant or only with a simple pan, whereby the gold nuggets or gold plates sediment on the ground or edge of the pan due to their high density.
Today, two industrial methods are the most important ones: During amalgation, the rock containing the gold is crushed in mills and mixed with water and mercury. The gold creates an alloy (amalgam) with the mercury, from which the mercury can be distilled off through distillation at 600°C. About two thirds of the gold can be extracted from the rock with this method. To extract the remaining gold, cyanide leaching is required, which was invented in 1887 by Scotsmen MacArthur and Forrest. In this method, the finely crushed rock is mixed with sodium or potassium cyanide solution with the addition of atmospheric oxygen. The gold enters into a complex cyanide compound, from which it can be extracted purely through reduction with zinc shavings. The gold drops to the grounds as a sponge. The precipitation is filtered, dried and roasted, then melted with the help of a flux, such as Borax, and melted into bullions.

Application:
For a long time, gold was an important currency metal, but this has no longer been the case since 1978. Nevertheless, some two thirds of gold reserves are kept in state deposits as currency reserves. In technology gold has, in contrast to platinum, only a very minor significance, as cheaper replacement substances have become available in the meantime. It plays an important role in dental medicine as dental gold, in electronics for the production of switch contacts and in optics for the production of high-quality mirrors, sun protection glasses and reflectors for satellites. Galvanic gold plating of objects for the protection against corrosion is of some significance in space travel in particular. The gold leaf with a thickness of 0.1 micrometres is used to adorn objects or restore objects of art. As Purple of Cassius, gold was occasionally used to colour glass and porcelain. Such glasses turn into a rich ruby colour, which is down to the existence of colloidal gold.
So why you must be wondering is my blog about gold? Well my offline work involves marketing stock in gold a processor and as a result I have come across a 16 year old German company with its own mine and processing plant with secure storage in St. Gothard Massif, Switzerland and we can get involved in gold investments and build a residual income for ourselves. This is not coins but pure 1,2 and 5 gram 24 Carat  – 999.0 fine gold!

No comments:

Post a Comment