The Hindu Business Line : Gold facts

The US owns the most gold, followed by Germany and the International Monetary Fund. India emerges as the largest repository of gold within the national boundaries, if jewellery is included.

GOLD is a rare metallic element with a melting point of 1064 degrees centigrade and a boiling point of 2808 degrees centigrade.

The word `gold' appears to be derived from the Indo-European root `yellow', reflecting one of its most obvious properties. This is reflected in the similarities of the word in various languages: Gold (English), Gold (German), Guld (Danish), Gulden (Dutch), Goud (Afrikaans), Gull (Norwegian) and Kulta (Finnish).

According to the World Gold Council, at the end of 2001 all the gold ever mined stood at around 145,000 tonnes.

The reason why gold was measured in carats dates back to ancient times in the Mediterranean and the Middle East, when a carat became used as a measure of the purity of gold alloys. The purity of gold is now measured also in terms of fineness, parts per thousand. Thus 18 carats is 18/24th of 1000 parts = 750 fineness.

A carat was originally a unit of mass based on the Carob seed or bean used by ancient merchants in the Middle East. The Carob seed is from the Carob or locust bean tree. The carat is still used as such for the weight of gemstones (1 carat is about 200 mg). For gold, it has come to be used for measuring the purity of gold where pure gold is defined as 24 carats.

In terms of national gold reserves, the US owns the most gold, followed by Germany and the International Monetary Fund. If jewellery is included, India emerges as the largest repository of gold in terms of total gold within the national boundaries.

According to WGC, the gold so far produced if stretched into a thin wire of 5-micron diameter, then all of it would stretch around the circumference of the world 72 million times approximately.

Gold production has been growing for years, but the jump came in the late 1970s, when output was in the region of 1,500 tonnes a year.

Gold mining, says WGC, is very capital intensive. "Particularly in the deep mines of South Africa where it is carried out at depths of 3,000 metres and proposals to mine even deeper at 4,500 metres are being pursued." Mining costs are in the range of $238/troy ounce gold average but these can vary widely depending on mining type and ore quality. Richer ores mined at the surface (open cast mining) is considerably cheaper to mine than underground mining at depth. Such mining requires expensive sinking of shafts deep into the ground.

The gold-containing ore has to be dug from the surface or blasted from the rock face underground. This is then hauled to the surface and milled to release the gold. The gold is then separated from the rock (gangue) by techniques such as flotation, smelted to a gold-rich doré and cast into bars.

These are then refined to gold bars by the Miller chlorination process to a purity of 99.5 per cent. If higher purity is needed or platinum group metal contaminants are present, this gold is further refined by the Wohlwill electrlytic process to 99.9 per cent purity. Mine tailings containing low amounts of gold may be treated with cyanide to dissolve the gold and this is then extracted by the carbon in pulp technique before smelting and refining.

Gold is made into a large number of different bars of different weights. The most well-known are the large London Good Delivery Bars, which are traded internationally. These weigh about 400 troy ounces or 12.5 kg each.

All metal atoms are made of the same building blocks of protons, neutrons and electrons, but in different quantities, so in theory it could be possible to change base metals into gold or any other metal of value to mankind. In practice, it is achieved only in nuclear reactions, where heavy radioactive metals decay into other lighter elements, including some isotopes of gold.

"However, man's ancient dream of turning base metals into gold is not a practical proposition. So it remains a dream," says the WGC.

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