The Gold formation

Gold is a precious thing which is found  it the  crust layer of the earth The  gold is transported though the Earth’s crust dissolved in warm to hot salty water. These fluids are generated in huge volumes deep in the Earth’s crust as water-bearing minerals dehydrate during metamorphism. .while its overall concentration is very low , rich concentrations of gold, forming ore deposits, are known throughout the world.
Any gold present in the rocks being heated and squeezed is sweated out and goes into solution as complex ions. This direction is generally upwards, to cooler regions at lower pressures nearer the Earth’s surface. Under these conditions, the gold eventually becomes insoluble and begins to crystallise, most often enveloped by masses of white silicon dioxide, known as quartz.  Veins and reefs of gold-bearing quartz can occur in many types of rock, for example around granites, in volcanic rocks or in regions of black slate, but in most cases these host rocks are not the immediate source of the gold.

The Gold deposits have formed at many different times during Earth’s history. For example, it is believed to have formed about 2400 million years ago, during a period of intense metamorphism and intrusion of igneous rocks. As a chemical , weathering and erosion gradually break down the host rocks and lower the land surface, the quartz and gold veins are eventually exposed to the atmosphere. The veins provide far more resistance to chemical attack than the surrounding rocks, so that mechanical weathering is required to fragment the quartz, thereby releasing the gold.  Because they are relatively heavy, particles of gold are more difficult to move and so become naturally concentrated in the soil.
These were especially important in the Ballarat district. Because of its resistance to chemical attack, gold can be recycled from one type of alluvial deposit to another. Thus Gold is extracted from sandy soil rich in gold for this the sandy soil is mixed with water and run on a sluice. By this process, gold gets trapped inside the blocks of sluice and is separated from the sand . in this way the gold is formed from the sand.