From time immemorial to the present day, gold has been widely used in many areas of human activity. It is used in the jewelry industry, the financial sector, industry and other spheres of business. In this article we will tell you about interesting, but little-known facts about this noble metal.
South of Cairo, in the sands of the desert, is the world's oldest gold mine, dating back five thousand years.
In 1947, American physicists Ingram, Hess and Haydn carried out an experiment to measure the effective absorption cross section of neutrons by mercury nuclei. As a side effect of the experiment, about 35 μg of gold was obtained. Thus, the age-old dream of alchemists was realized - the transmutation of mercury into gold.
Gold is so rare that more steel is cast all over the world in one hour than gold has been cast in the entire history of mankind. In 2011, 2, 8 thousand tons of gold were mined in the world, with the PRC, Australia and the USA becoming the leaders in production.
Gold is also highly plastic: it can be forged into sheets up to ~ 0.1 microns thick (gold leaf); with such a thickness, gold is translucent and in reflected light has a yellow color, in transmitted light it is colored bluish-greenish, complementary to yellow. Gold can be drawn into wire with a linear density of up to 500 m / g.
Throughout the history of our planet, according to various estimates, from 150 to 200 thousand tons of gold have been mined, while during this time humanity has lost only 10-15%. In addition, at least 15% of the annual gold consumption is recycled. This suggests that your chances of wearing a ring or other piece of jewelry with prehistoric gold particles are very high.
Geologists claim that all gold-bearing corners of the planet have already been explored, and estimate the mass of the precious metal at 120-150 thousand tons.
The largest reserves of gold on earth are found in its core. They are 5 times higher than all known and available for development reserves in all other rocks. If the surface of the Earth were covered with gold from the core, then the thickness of the layer would be half a meter.
Gold is a very ductile metal and, at the same time, very heavy. It is so plastic that from a piece weighing 1 g. wire 3 km long can be forged. Or roll such a piece into foil, which will be 500 times thinner than a human hair. At the same time, gold is so heavy that a cube of precious metal with a side of only 37 cm will weigh a whole ton.
The largest nugget in the world was found in Australia in 1872 and was named the Welcome Stranger. It was a solid lump of gold 25 by 63 cm in size and weighing about 70 kilograms. Today the nominal value of such an ingot would be UAH 35 million.
If a gold ring is worn from adulthood to death, it will become twice as thin. It is interesting that the smallest particles of gold are on all people who work with gold or simply store it. These particles constantly separate from the gold and settle on human skin, cling to clothing, or settle on objects in the room where the gold is stored. If you burn the fabric that is used in such places for upholstery, and then, after taking apart the ash, you can find a small piece.
Gold is practically resistant to chemical attack. It can only be dissolved in aqua regia - a special mixture of concentrated acids, hydrochloric and nitric. In addition, gold dissolves in alkaline solutions of potassium or sodium cyanide.
Pure gold (999 carat) is too soft to keep its shape. Jewelry is made from special alloys of gold with other metals. The amount of pure gold in the alloy is determined by the fineness. For example, in alloy 585, 1 gram contains 0.585 mg. gold.
Recently released tablets for those wishing to defecate in gold. These 2cm long yellow capsules sell for $ 425 per pack of three. It is enough to swallow such a pill and the feces take on a golden color.
Currently, the world's bank gold reserves are estimated at 32 thousand tons. If you fuse all this gold together, you get a cube with a side of only 12 m.The largest gold holders are the USA (8, 100 tons), Germany (3, 400 tons) and the International Monetary Fund (2, 8 thousand tons)