Gold is widespread in all parts of the globe, there are gold free in nature, and multiplicity attributes make him a world renown since the time, is one of the most expensive metals price throughout the ages, it is more metal when scientists, writers and readers know the metal because of its spread, and use money in various parts of the world.
Gold as the yellow metal scholars shining body blocks can reflect light, and gold in the transitional group number 11 on the periodic table, atomic number 79, atomic weight of 196.967 and a weight of qualitative 19.3.
And you melt gold at $ 1063 ° c and boil at 2500 c.
Gold good conductor of heat and electricity, and no more such little silver and copper sheets tortillas appears green or blue.
And also described pieces of gold section carefully cut you, they are black, while other types of gold ranging in color from Sapphire and purple.
Start a knowledge of history with gold in the 10th century, with the arrival of Islamic civilization to their best phase, the Princes and the Caliphs are mansions, jewelry and metals brought from various parts of the vast Muslim State.
And has many ways to extract gold and purified, and many of the chemical explanation of these methods, either through the drain, with fire as melting alone, gold United stone like a foundry, and mercury and gold called Gold Mercury and gold reached the end up behind a draw.
And purifies the newly separated gold dust, silt and other bug aqueous streams by strong Sandy alluvial minutes, remove and keep minutes of gold in place due to the high density of the gold or gold recovery which tightens as the cyanide method, or melt the silver alloys in concentrated sulfuric acid, and the purification of gold in nitric acid and electrolysis.