GOLD

Gold is a chemical element within the periodic table that has the symbol Au (Latin: 'Aurum') and atomic number 79. A transition metal (trivalent and univalent) a soft, shiny, yellow, heavy, "malleable", and "ductile". Gold does not react with other chemicals but attacked by chlorine, fluorine and aqua regia. The metal is widely available in gold nuggets or dust on the rocks and in alluvial deposits and one of the Coinage metals. ISOnya code is XAU. Gold melt in liquid form at temperatures around 1000 degrees centigrade.

Gold is a metal which is soft and malleable, hardness ranged between 2.5 - 3 (Mohs scale), and its density depends on the type and content of other metals mixed with it. Mineral carrier of gold is usually associated with minerals (gangue minerals). Associated minerals are generally quartz, carbonate, tourmaline, flourpar, and a small amount of non-metallic minerals. Gold mineral carrier is also associated with sulphide deposits that have been oxidized. Mineral carrier of gold consists of gold nativ, elektrum, telurida gold, some gold alloys and compounds with the elements sulfur, antimony, and selenium. Elektrum actually another type of gold nativ, only the content of silver in it> 20%.

Gold magmatisme formed from the process or the concentration at the surface. Some precipitate formed by the process metasomatisme contact and hydrothermal solution, whereas the concentration of sediment yield put mechanically (placer). Genesis of gold be categorized into two namely:

* Deposition primary; and

* Deposition plaser.

Monetary gold as collateral for the currency that had been used by Bank Indonesia

Gold is used as a financial standard in many countries and is also used as jewelry, and electronics. The use of gold in monetary and financial field based on absolute monetary value of gold itself against various currencies around the world, although officially in world commodity markets, gold prices are listed in U.S. Dollars. Shape the use of gold in the monetary field is typically in the form of bouillon or gold bullion in various units of weight grams to kilograms.

Gold Coins

Gold is also traded in the form of gold coins, such as the Krugerrand which is produced by the South African Mint Company in a variety of unit weight. Unit weight is commonly encountered Krugerrand 1 / 10 oz (ounce), 1 / 4 oz, 1 / 2 oz and 1 oz. Krugerrand coin prices based on gold price movements in world commodity markets continue to move along the trade. Krugerrand Coins special (or so-called proof collector edition) also produced a limited basis in accordance with a specific theme. Due to limited production, often times the issue price of the proof Krugerrand coins exceeds the price of gold content of coins depends on scarcity and condition of this particular coin. Edition is quite popular and sought investors is the edition that contains the image of Nelson Mandela.

There are several countries that produce a mass of gold coins to be offered as an alternative investment, among others:

1. Australia - kangaroo

2. China - panda

3. Malaysia - golden deer

4. Canada - maple leaf

5. UK - Britannia

6. United States - eagle and buffalo

7. South Africa - Krugerrand

8. New Zealand - Kiwi

9. Singapore - Lion

10. Austria - the Philharmonic

The price of gold

In a long and tortuous history, the current gold arrived in a new era with the opportunities and dangers. Current gold price is higher than the price of the last 17 years, soared to $ 1,000 per troy ounce. (1 ounce = 31.1035 grams). However, gold is very little left to be mined from the earth and have been squeezed by the cost of environmental recovery are very high and not infrequently in the poorest parts of the world.

In fact, as of March 2008, the price of gold reached U.S. $ 1,010 per troy ounce (troy ounce = 31.1035 grams) or equivalent to Rp 298,000 per gram. The price of gold in August 2011 has touched U.S. $ 1700 per troy ounc averaged 520 000 per gram.

Estimated 2008

Gold prices rose in 2008 related to interest Americans who plan to cut interest rates again, but it is pointed out as a projection on the huge demand in the market for gold jewelry. It is also confirmed by the National Australian Bank (NAB) on minerals and energy sector.

Advantages and poverty

Today gold companies invaded the corners of the earth is guided by a guide who is strong: the World Bank. World Bank, the lead agency that spicy finish of world poverty, assume that multinational mining companies would bring investment, encouraging the construction of roads, schools and jobs, to countries that do not have a lot of capital in addition to their natural resources.

The World Bank's work on both sides. At his urging, more than 100 governments are experiencing financial problems agreed to cut taxes and royalties to lure big mining companies, said James Otto, a visiting professor at the University of Denver law school.

Meanwhile, the World Bank gave money to or guarantee more than 30 gold mining project, for profit.

Although mine is only a small part of the World Bank's portfolio, when controversy was rampant accidents increased. In one of the worst disasters, in 1995 a mine in Guyana which is guaranteed by the World Bank to shed more than 790,000 gallons of mine waste mixed with cyanide to child Essequibo River, which is the country's main water source.

In 2001, the World Bank president, James D. Wolfenshon, set a moratorium on mining investments over the past two years and ordered the preparation of a study of World Bank involvement in the industry.

Gold deposit in Indonesia

The potential of gold deposits found in almost every region in Indonesia, such as in Sumatra, Riau Islands, the island of Borneo, Java, Sulawesi, Nusa Tenggara, Maluku and Papua.

Gold Extraction

Amalgamation

Amalgamation is the process penyelaputan gold particles by the mercury and form amalgam (Au - Hg). Amalgam is still the gold extraction process the most simple and inexpensive, but effective process for high-grade gold ore and has a coarse grain size (> 74 microns) and in the form of pure gold that is free (free native gold).

The process of amalgamation is a process of chemical physics, amalgamnya when heated, it will break down into elements of mercury and gold bullion. Amalgam can be decomposed by heating in a retort, the mercury will evaporate and can be recovered from the condensation of mercury vapor. While the Au-Ag remained behind in the retort as a metal.

Cyanidation

Cyanidation process consists of two important stages, namely the dissolution process and the process of separating gold from the solution. Solvents commonly used in the process cyanidasi is NaCN, KCN, Ca (CN) 2, or a mixture of all three. The solvent most often used is NaCN, being able to dissolve gold better than any other solvent. Generally, Au and Ag leaching reaction is as follows:

4Au 8CN-+ + O2 + 2 H2O = 4Au (CN) 2 - + 4OH-

4Ag 8CN-+ + O2 + 2 H2O = 4Ag (CN) 2 - + 4OH-

In the second stage of the separation of metallic gold from the solution is done by precipitation using zinc powder (Zinc precipitation). The reaction is as follows:

2 Zn + 2 NaAu (CN) 2 +4 +2 NaCN Au H2O = 2 NaOH + 2 + 2 Na2Zn (CN) 4 + H2

2 Zn + 2 NaAg (CN) 2 NaCN + 4 H2O = 2 +2 Ag + 2 NaOH + 2 Na2Zn (CN) 4 + H2

The use of Zn powder is one effective way to a solution containing a small concentration of gold. Zn powder were added into the solution will precipitate the metals gold and silver. The principle is based deposition Clenel series, based on sequence differences in electro chemical activity of metals in cyanide solutions, namely Mg, Al, Zn, Cu, Au, Ag, Hg, Pb, Fe, Pt. each metal is located on the left of the complex bond sianidanya can precipitate the metal it replaces. So in fact not only can urge Zn Au and Ag, but Cu and Al can also be used, but because it is more expensive then it is better to use Zn. Making processes of gold-silver-rich solutions using Zn powder is called "Merrill Crowe Process".