In hydrothermal processes, veins of minerals or metals are formed when sheet-like deposits precipitated by hot water solutions that fill fractures in the earth or deposit near igneous regions. Crystal settling occurs when mineral particles in a cooling magma chamber crystallize and sink to the bottom. Ore extraction is a complex, and often dirty process. It is first dug up, then crushed and chemically seperated from surrounding materials. Large piles of waste rock are left and allowed to erode into water supplies, harming aquatic habitats.
Mining also ruins landscapes by contributing to deforestation, air and water pollution.
Such pollution endangers the lives of all populations in the environment. The growth rate of plants is slowed, causing the growth rate of the entire food chain to decrease. The people who live and work by these mining sites are plagued with lung and skin cancer as a result of harmful biproducts. Bertle and Anaconda, Montana comprise an area of 10 square miles of mines and mills. Waste piles from these sites are an average of 50 feet in height, equivalent to that of a five story building.