Heavy metals can be formed naturally. There are seven heavy metal formation process in nature, is segregation directly with magma, magma intrusion, pregmatit body building, involvement of hydrothermal solutions, power influence in the soil solution, the secondary effects of water resources, and the process of sedimentation.
Segregation directly with magma occurs when the grain has a greater density mengendapa through molten magma during crystallization takes place.
Magma intrusion occurs when a chemical solution that is very active in the rock surrounding the magma change.
Pregmatit body formation occurs when the body is more coarse-grained material in the mass of plutonic rocks that host the finer grained.
The involvement of hydrothermal solution occurs when a metal left at the end of the crystallization of magma and sediment in the rock forming mineral veins.
Power influence soil solution occurs when deposits were dissolved in water percolation, accumulate and become concentrated, so the bottom into the soil solution.
Secondary processes influence water resources occurs when the residual metal forming. This process occurs in water infiltration and percolation moving experience higher levels of soluble rather than substance – a substance that contains metal.
The process of sedimentation occurred on land and sea. Rocks undergo weathering then carried by the flow into the river and downstream. After that rocks containing heavy metals will precipitate first next upstream than that do not contain heavy metals because it has a higher specific gravity.