Gold is the most prized and renowned of all metals that ever existed. The uniqueness, exquisiteness and mystery of Gold have made it a commendable commodity all through the history of civilization.
Gold occupies the first place in the category of minerals, which accounts for its popularity and fame. Since time immemorial gold has earned fame for its worth and exceptional properties. The majority of samples of gold occurred in nature, and were discovered ages ago and smelted for the purpose of converting it into products.
Pure gold is malleable and compressible, while jewelry made of gold is not pure; it is alloyed with other metals to enhance its durability and toughness.
The mineral gold, obtained in nature is found to possess small quantities of silver and copper. A rough lump of Gold normally contains 70 – 95% gold, the rest is silver. Genuine gold is brilliant golden yellow in color. More silver content in gold turns its color whitish. The majority of mined gold is from its ore and they are not genuine samples of gold. The ore of gold possesses only very small quantities of gold, the ore is normally brown, a rock stained with iron, or a huge white quartz. Gold is extracted from gold mines by merely crushing the ore and further separating the gold by some means.
Gold is obtained in significant quantities in the following three main deposits: in Volcanic exhalative sulfide deposits; hydrothermal quartz veins and connected deposits in metamorphic and igneous rocks; and in unconsolidated to consolidated placer deposits. There is also possibility for it to occur in contact metamorphic or hypothermal deposits, (e.g. Skarns). Or epithermal deposits like volcanic fumaroles. The most common occurrence of gold is either in the form of distributed grains in the veins of quartz along with pyrite and several sulfides or obtained as round grains, as flakes or in the placer deposits as nuggets in the deposits of rivers or in the deposits of very old streams. These deposits of gold are normally panned to extract gold. The density of gold is very high: therefore on panning, the other lighter sediments get washed away from the pan or sluice. The World Gold Council regulates gold prices worldwide,
Derivation of the Name
Gold earned its name from the ancient English word geolo, which means Yellow.
The symbol of gold in the periodic tables is given as Au, which is its chemical formula, derived from the Latin word “Aurum", meaning gold.
Color – metallic yellow
Luster – Metallic
Fracture – Hackly
Transparency – Opaque
Associated minerals – Gold is normally correlated with pyrite and several sulfides. These correlated minerals have a resemblance of gold in appearance; therefore sometimes it becomes difficult to identify gold from them. In some cases gold associated with these minerals is heated sufficiently high, so that the sulfide whose melting point is lower than gold dissolves away and the gold is left over in the matrix. This gold is called “Roasted Gold", which at times is marketed to collectors.
15.5 to 19.3
Does not tarnish
Golden-yellow in color
Ductile and malleable
2.5 to 3 Mohs
Gold is used to a wide extent in the manufacture of jewelry for making bracelets, rings, earrings, necklaces and many more items of jewelry. As far as manufacture of jewelry is concerned, gold is the most precious metal and its price is highest among mineral/ metals In the pre-historic ages, gold masks and other ornaments were made of use, besides in ancient times gold coins were manufactured.
Gold is used in fiscal standards, today all over the universe; we find antiques of gold jewelry and several other ornaments that date back to centuries. Gold was and is at all times considered the most precious of all jewelry items,
A radioactive isotope of gold (gold-198) is used for cancer treatment
Gold sodium thiosulfate (AuNa306S4) used in other treatments.
Chloroauric acid (HAuCL4) used in photographic preservation.
It is the belief of Indians that a wedding is incomplete without Gold
Since thousands of years ago, gold has been considered the most precious metal for making jewels and objects of ornamental use. The Gold nugget discovered in the streams is easily worked, Gold was the first metal that human beings made use of. At present the majority of Gold freshly mined or that are recycled is used in jewelry. Approximately 78% of the gold is worked on every year in manufacturing jewelry.
Gold is resistant to tarnish, extremely high in luster, ductile, appreciable yellow color, malleable, these are the essential properties to work on with ease and convert to pretty objects. Traditional use is the most essential reason for Gold to have demand. Gold is the only metal used for making valuable objects.