1. GOLD

2. The value of gold is of course a result of its rareness and also of its interesting physical characteristics.
Gold is a so-called precious metal, which means it does not rust (oxidise) at normal conditions.
It is resistant against many acids and a good electric conductor, which makes it useful for electronic circuits.
It is also useful for jewelry because of its inertness, as it will not oxidise or change in any other way.
The continually high value of gold made it an important factor for money.
Originally the most valuable coins were made of gold. Later, when people found gold too heavy and difficult to handle, paper money was invented, which was just a sort of paper representation of the gold value.
A good example is the British Pound, which originally corresponded with a pound of Sterling Silver.

3. Gold is normally found in pure form
Gold is normally found in pure form. This means it is not oxidised and it is not necessary to process it very much. But the amounts of pure gold are typically very little as it is normally evenly distributed in the rock.
There are several geologic processes which accumulate gold, most important for classic gold fields is erosion. The rock is eroded, the gold remains, and the small pieces of gold are washed into the next stream. But gold is very heavy, and so it tends to deposit in holes on the ground of rivers, a deposit called placer.

4. Other deposits are poly metallic deposits, where hydrothermal processes, often in combination with sulphuric chemical reactions, deposited large amounts of different metals in submarine depressions or in clefts.
Typically gold is the rarest metal in the ore, but depending on the percentage and the value, it may be the most valuable part.
As it is rather easy to process those ores in furnaces and separate the different metals, those deposits are mine since the early Middle Ages.

5. Methods
Placer mining
Panning : Gold panning is mostly a manual technique of separating gold from other materials. Wide, shallow pans are filled with sand and gravel that may contain gold. The pan is submerged in water and shaken, sorting the gold from the gravel and other material. As gold is much denser than rock, it quickly settles to the bottom of the pan. The panning material is usually removed from stream beds, often at the inside turn in the stream, or from the bedrock shelf of the stream, where the density of gold allows it to concentrate, a type called placer deposits.
Gold in gold pan—Alaska

6. Gold sluicing at Dilban Town, New Zealand, 1880s
Sluicing : Using a sluice box to extract gold from placer deposits has long been a common practice in prospecting and small scale mining. A sluice box is essentially a man made channel with riffles set in the bottom. The riffles are designed to create dead zones in the current to allow gold to drop out of suspension. The box is placed in the stream to channel water flow. Gold bearing material is placed at the top of the box. The material is carried by the current through the box where gold and other dense material settles out behind the riffles. Less dense material flows out of the box as tailings.
Taking gold out of a sluice box, western North America, 1900s

7. Dredging
Although this method has largely been replaced by modern methods, some dredging is done by small scale miners using suction dredges. These are small machines that float on the water and are usually operated by one or two people. A suction dredge consists of a sluice box supported by pontoons, attached to a suction hose which is controlled by a miner working beneath the water.
Cradle
A cradle rocks back and forth while water was poured over it. The sand and gravel was washed through the screen of the cradle, leaving the gold behind

8. Hard rock mining
Hard rock gold mining extracts gold encased in rock, rather than fragments in loose sediment, and produces most of the world's gold.
Sometimes open-pit mining is used, such as at the Fort Knox Mine in central Alaska. Barrick Gold Corporation has one of the largest open-pit gold mines in North America located on its Goldstrike mine property in northeastern Nevada.
Other gold mines use underground mining, where the ore is extracted through tunnels or shafts. South Africa has the world's deepest hard rock gold mine up to 3,900 metres (12,800 ft) underground. At such depths, the heat is unbearable for humans, and air conditioning is required for the safety of the workers. The first such mine to receive air conditioning was Robinson Deep, at that time the deepest mine in the world for any mineral.
Hard rock mining at the Associated Gold Mine, Kalgoorlie, Australia, 1951
Gold mining in Coromandel Peninsula,New Zealand in the 1890s
Gold bearing quartz veins in Alaska

9. WORLD PRODUCTION OF GOLD
Mine production Reserves e
United States ,000
Australia ,300
Brazil ,400
Canada
Chile ,400
China ,900
Ghana ,400
Indonesia ,000
Mexico ,400
Papua New Guinea ,200
Peru ,000
Russia ,000
South Africa ,000
Uzbekistan ,700
Other countries ,000
World total (rounded) 2, , ,000
Reserves estimates for Australia, Chile, and Peru were revised based on new information from government reports.
e. Net bullion flow (in tons) to market from foreign stocks at the New York Federal Reserve Bank: 0 (2006), 189 (2007), 220 (2008), 0 (2009), and 0 (2010 estimate).

15. DISTRIBUTION
South Africa-backbone of economy. Produces 35% of world gold.
Rand Fields (Witwatersrand)-located in Southern Transvaal.142km long and 42km broad having 8 zones.
Western mines of Kimberlay, Bird Reefs and the Livingston Reefs
Johannesburg important centre for refining
Other areas are Cape of Good Hope, Natal and Orange Free State.
Russia
Urals, Trans-Baikal and Lena Basin.
USA
California, Arizona, North Dakota, Colorado, Idaho, Montana, Alaska (Yukon and Fairbanks Districts)

16. South America- very small quantities
Canada
Canadian Shield important mining area. Gold is found from western Quebec to North West Territory.
Ontario produces 60% and Quebec 20% of country’s gold.
West British Colombia.
Australia
Western Australia-vast desert expanse gold mines scattered
Coolgardie, Kalgoorlie, Yampi
Queensland
Mount Morgan, Charles Towers
Victoria
Bendigo, Poseidon, Ballarat
India
Karnataka
Kolar gold fields (Kolar district), Hutti mines (Raichur district)
Andhra Pradesh
Ramagiri amd Anantpuram district and Chigargunta in Chitoor district.
Mexico
Durango, Hiddgo, Gualjo
South America- very small quantities
Brazil, Peru, Bolivia and Colombia