Quick Fact Sheet : Gold
2. Gold has traditionally found use because of its good resistance to oxidative corrosion.
3. It is attacked by aqua regia* (a mixture of acids), forming chloroauric acid and by alkaline solutions of cyanide but not by single acids.
4. * Aqua regia (Latin for royal water) is a highly corrosive, fuming yellow or red solution. The mixture is formed by freshly mixing concentrated nitric acid and concentrated hydrochloric acid, usually in a volumetric ratio of 1:3 respectively. It was so named because it can dissolve the so-called royal, or noble metals gold and platinum, although tantalum, iridium, osmium, titanium and a few other metals are able to withstand it.
5. The gold content of gold alloys is measured in carats (k), pure gold being designated as 24k.
6. Since the abandonment of the gold standard* and the forced conversion of bullion gold and
circulating gold to silver in 1933 by the United States Government, gold has not generally been used in daily commerce.
7. The gold standard is a monetary system in which a region’s common media of exchange are paper notes that are normally freely convertible into pre-set, fixed quantities of gold. The gold standard is not currently used by any government, having been replaced completely by fiat currency.
8. The concentration of free electrons in gold metal is 5.90×1022 cm-3.
9. Gold is highly conductive to electricity, and has been used for electrical wiring in some high energy applications (silver is even more conductive per volume, but gold has the advantage of corrosion resistance).
10. As a measure of purity, one carat is purity by mass:
X=24*Mg/Mm
Where
X is the carat rating of the material,
Mg is the mass of pure gold or platinum in the material, and
Mm is the total mass of the material.
Therefore 24-carat gold is fine (99.9% Au w/w), 18-carat gold is 75% gold, 12-carat gold is 50% gold, and so forth.
11. Historically, in England the carat was divisible into four grains, and the grain was divisible into four quarts. For example, a gold alloy of fineness (that is, 99.2% purity) could have been described as being 23-carat, 3-grain, 1-quart gold.The carat system is increasingly being complemented or superseded by the millesimal fineness system in which the purity of precious metals is denoted by parts per thousand of pure metal in the alloy.
12. The most common carats used for gold in bullion, jewellery making and by goldsmiths are:
24 carat (millesimal fineness 999)
22 carat (millesimal fineness 916)
20 carat (millesimal fineness 833)
18 carat (millesimal fineness 750)
15 carat (millesimal fineness 625)
14 carat (millesimal fineness 585)
10 carat (millesimal fineness 417)
9 carat (millesimal fineness 375)
8 carat (millesimal fineness 333)
1 carat (millesimal fineness 042)
13. Chip Gold is a gold ingot vacuum-sealed in a package in the shape of a credit card. It is meant to be used as a tangible and liquid investment in gold bullion. The packaging ensures the consumer/investor that the gold within is of stated purity and weight. Typically, weights available are 1g, 2.5g, 5 g, 10g, and 20g, 1/4 Ounce, 1/2 Ounce, 1 Ounce and the purity is .9999 (at least 99.99% pure gold).
14. White gold is an alloy of gold and at least one white metal, usually nickel or palladium. Like yellow gold, the purity of white gold is given in carats. White gold’s properties vary depending on the metals and proportions used. As a result, white gold alloys can be used for different purposes; while a nickel alloy is hard and strong, and therefore good for rings and pins, gold-palladium alloys are soft, pliable and good for white gold gemstone settings, sometimes with other metals like copper, silver, and platinum for weight and durability, although this often requires specialized goldsmiths.
15. Rose gold is a gold and copper alloy widely used for specialized jewelry due to its reddish color. It is also known as pink gold and red gold. As it was popular in Russia at the beginning of the nineteenth century, it is also known as Russian gold.
16. Green gold alloys are made by leaving the copper out of the alloy mixture, and just using gold and silver. It actually appears as a greenish yellow, rather than as green. Eighteen carat green gold would therefore contain a mix of gold 75% and silver 25%. Fired enamels adhere better to these alloys.
17. The first gold coins in history were coined by Egyptian Pharaohs around 2,700 BC. These gold coins, of variable purity, were used primarily as gifts and not for commerce. Several centuries later, King Croesus, ruler of Lydia between 560-546 BC, began issuing gold coins, with a standardised purity, for general circulation. King Croesus’ gold coins follow the first silver coins that were minted by king Pheidon of Argos around 700 BC.
18. The Ying Yuan was another gold coin minted during this time by the Chinese in the 6th or 5th century BC. Larger units of monetary value and exchange such as the talent were the ancient equivalents of the modern 400 troy ounce “good delivery” gold bullion bar.
19. Gold Investment: Today, like all investments and commodities, the price of gold is ultimately driven by supply and demand. Unlike most other commodities, the hoarding and disposal plays a much bigger role in affecting the price, because most of the gold ever mined still exists and is potentially able to come on to the market for the right price.
20. According to the World Gold Council, annual mine production of gold over the last few years has been close to 2,500 tonnes. About 2,000 tonnes goes into jewelry or industrial/dental production, and around 500 tonnes goes to retail investors and exchange traded gold funds. This translates to an annual demand for gold to be 1000 tonnes in excess over mine production which has come from central bank sales and other disposal.
21. Central banks and the International Monetary Fund play an important role in the gold price. At the end of 2004 central banks and official organizations held 19 percent of all above-ground gold as official gold reserves.
22. The Washington Agreement on Gold (WAG), which dates from September 1999, limits gold sales by its members (Europe, United States, Japan, Australia, Bank for International Settlements and the International Monetary Fund) to less than 400 tones a year. European central banks, such as the Bank of England and Swiss National Bank, have been key sellers of gold over this period. Although central banks do not generally announce gold purchases in advance, some, such as Russia, have expressed interest in growing their gold reserves again as of late 2005. In early 2006, China, which only holds 1.3% of its reserves in gold, announced that it was looking for ways to improve the returns on its official reserves. Some bulls hope that this signals that China might reposition more of its holdings into gold in line with other Central Banks.
23. Gold fingerprinting is a method for identifying a particular item made of gold based on the impurities or trace elements it contains. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) is used to characterize a gold-containing item by its trace elements, a.k.a. fingerprinting the sample by mineralizing event and to the particular mine or bullion source. This technique has been used to lay claim to stolen or relocated gold. Even gold that has undergone salting can be identified as to its multiple sources.
24. Gold & India
25. Deccan Gold Mines Limited (DGML) is the first private sector gold exploration company in India to be listed on the Mumbai Stock Exchange. Established as a gold exploration company in 2003, DGML now has a large portfolio of exploration prospects in the states of Karnataka, Andhra Pradesh, Kerala and Rajasthan.
26. Kolar Gold Fields (KGF) was one of the major gold mines in India and is located in the Kolar district in Karnataka, close to the city of Bangalore. It was closed in 2003 due to reducing deposits and increasing costs. The mine is considered the world’s second deepest gold mine.
27. India is the largest importer and consumer of gold in the world; but gold mining remains at very low levels. The country imported an estimated 443 tonnes of gold during in the first six months of the current fiscal, valued at $5.82 billion. But the country’s domestic gold production was at 3.05 tonnes during the financial year 2006.
28. Faced with the low production of gold, the Indian government has asked domestic gold miners to actively explore joint venture with foreign companies to speed up exploration of the yellow metal within the country.
29. What is the process of exploration for gold deposits in India, and how it is done?
Following are the seven steps to gold mining in India.
1: Literature Survey: There are a number of government agencies that carry out verification surveys on gold mining in India. The main among them are Geological Survey of India and Mineral Exploration Corporation of India. These agencies have already carried out extensive regional and detailed surface and underground exploration for gold in different parts of the country. The geological and exploration data generated by these agencies are available in several publications of theirs respective agencies. Collection of all this literature, which facilitates picking up of targets for further probing, forms the first step in exploration process.
2: Geological Mapping: Preparation of a good geological map of the area of interest, initially on a regional scale (1:50,000) by taking up number of field geological traverses, and with the help of aerial photographs and landsat imageries is generally the next step.
3: Identification of Gold Bearing Zones: This is done by collecting rock chip samples from favourable locales for gold mineralization while preparing the geological map of the area. If the rocks are not exposed, geochemical methods like stream sediment sampling, soil sampling can be adopted to identify gold anomalous areas. Similarly geophysical methods can be deployed to locate any conductive or magnetic bodies below the soil cover. These targets will be explored by trenching and rock-chip sampling. Depending on the sampling results the target areas are demarcated for detailed sampling in three dimensions.
4: Three Dimension Sampling: Three dimension sampling of gold bearing zones is carried out by reverse circulation (RC) drilling and diamond core drilling. The RC drill is mounted on a truck and is easily mobile. The rock sample is obtained in the form of rock chips for every 1 m drilling. The RC drill can drill up to 100m a day and works on compressed air. The mobility of a diamond core drill is slow. In diamond core drilling, the rock sample is obtained in the form of solid core. Approximately 20 to 25 m can be drilled in a day depending on the hardness of the rock formation.
5: Estimation of Global Resource: Based on the three dimension sampling of the gold-bearing zone (ore body), i.e. length, width, depth and grade, a global resource of the gold deposit is estimated.
6: Pre-feasibility exploration: The global resource is further worked upon by close spaced diamond core drilling along length and dip of ore body and sampling to improve the reliability of the global resource estimate. It also helps in ascertaining whether the deposit is mineable or not.
7: Feasibility Exploration: Feasibility exploration involves additional extensive sampling on surface and underground. An open pittable resource of reasonable dimensions has to be further sampled on surface by very closed spaced drilling, bench cutting and bench sampling to delineate the mineable reserves and to demarcate ore from waste. A resource that could be exploited by only underground method of mining needs to be sampled by sinking shafts and developing ore body along its length. This sampling enables the delination of rich pockets of ore within the ore body and assessment of mineable reserves.
