Mining and Environmental Impact
Mining techniques vary considerably depending on the mineral or gemstone and type of deposit.
Mining exclusively for crystals such as quartz and amethyst is extremely rare, and is usually associated with metal mining. Most minerals used in crystal healing come from places like Minas Gerais in Brazil, which is connected primarily with gold mining. One exception is the quartz mine in Arkansas, which is a family-owned operation.
Mining for precious gemstones differs from much of the mining that produces other crystals and minerals. There are two main types of deposit, usually referred to as primary and secondary. If the deposit is still located in the original host rock it is considered to be primary. The crystals are in good condition, but in most cases the yield will be relatively small, and many tons of “deaf” rock (non-gem bearing rock) will have to be removed in the search for gemstones. Secondary deposits occur when gemstones have been transported from their place of formation, and deposited elsewhere. This can be by river, sea, coastal erosion, or even wind. The crystals are usually more rounded and small than those from a primary deposit, but will occur in greater concentration.
Diamond mining is big business and heavily regulated, and is the only area of gemstone mining in which there is a large capital investment available for serious prospecting. Most other deposits are discovered by accident. Mining techniques are usually primitive, and in some cases haven’t altered much in 2000 years. The easiest collection of gemstones is from surface deposits, for example dry riverbeds, rock crevices and caves. Other methods involve much more hard work.
Crystals imbedded in “deaf” or mother rock are removed with hand tools, pneumatic tools (compressed air) or blasting. If a secondary deposit is beneath another surface layer, either this layer is removed, or a shaft is built downwards. With minimal bracing these shafts can be up to 10m deep.
When prospecting in riverbeds, various sluiceways and dams are used to create particular water-flow conditions that will expose the gemstones.
As far as environmental impact of crystal mining is concerned, only diamond mining is done on a truly industrial scale, and usually employs strip-mining methods.
Mining and the Environment
Generally speaking, the small-scale mining described above has minimal environmental impact. However, there are issues in most types of mining that include destruction of landscapes and agricultural and forest lands, sedimentation and erosion, soil contamination and surface and groundwater pollution, air pollution, and waste management. Larger scale mining can be incredibly destructive, and in the case of metal ore, will create a great deal of pollution and use a large amount of fossil fuels in the smelting process. This type of mining is usually restricted to coal or metal mining.
One of the largest pollution problems is due to abandoned mines. Up until recently mining was not regulated, and miners or mining companies were not held responsible for restoring the mine or preventing and containing contamination either during or after the mine was in use. Water enters the mines, and if iron pyrite is present, it is easily broken down when suspended in water. Iron pyrite is a sulphide. It will release iron into ground water, which will create a reddish-brown suspension. The sulphide then becomes sulphuric acid, which breaks down other metals within the mine. The water finally emerging from the mine may be acidic and laden with metals such as copper, zinc and cadmium. Metal salts may also enter the water, making it saline. Treatment facilities are now usually installed at working mines to combat these potential problems, but abandoned mines are often left to continue damaging the surrounding area.
Another potential problem occurs when mining is not regulated as it should be. The large gold mines in Brazil, such as in the state of Minas Gerais, use deep shaft industrial mining, and adhere to local regulation. However, a lot of the gold mining in Brazil is done by entrepreneurs, and takes place deep in the Brazilian Amazon. It has been encouraged by the government, which chooses to turn a blind eye when regulatory practise is not strictly adhered to. This does not make a large impact on deforestation, as one would expect, but the techniques employed involve use of mercury to extract the gold, and also a great deal of water turbulence is created when separating the gold from the surrounding rock. Depending on the methods used, mercury does not always enter the water table, but often does, which can poison both the local wildlife and the human inhabitants of the area. Turbidity in the river can destroy the fish population, again affecting other life including human.
One other issue that arises through mining in Third World countries is the use of child labour, and poor adherence to health and safety. European importers are expected to know the working conditions of the mines they are purchasing their minerals from, and sign documentation confirming this. However, this is extremely difficult to regulate, as most importers buy from dealers, not directly from the mines, and are only able take the dealer’s word for the working conditions of the miners. Some importers are claiming to import only Fair Traded minerals, but these are mainly referring to the working conditions of the carvers in the factories.
In all developed countries and most developing countries there are strict regulations controlling mining, which include prevention of contamination of ground water and subterranean aquifers, both during the period of mining activity, and later when the mine is no longer in use. There will also be regulations in place to assure erosion is kept to a minimum, and often this will also involve replacing previously existing flora, or turning the area into a pleasant recreational site, such as a swimming hole, assuming there is no contamination in the water. Before a mine is opened, the company involved are expected to present an environmental impact assessment.
This is good news for the environment in general, but the effects of large-scale industrial mining and poor mining practises of the past are continuing to take their toll, and however much these practises have improved, most mining of any sort will have a negative impact on the environment.