Generic name for a group of fibrous mineral silicates. It includes blue asbestos (crocidolite), white asbestos (chrysotile) and brown asbestos (amosite). After they are mined the asbestos fibres are separated from the rock and are spun into a cloth. When inhaled the fibres penetrate the lungs and the tissues of the bronchial tubes, resulting in asbestosis, a crippling lung disease. Asbestos also causes cancer of the lung and the gastro-intestinal tract, and mesothelioma, a malignant cancer of the inner lining of the chest. However, because it is a poor conductor of electricity and highly resistant to heat it has been widely used over the years in fire-fighting suits, and building and insulating materials. The fibrous form of several silicate minerals, at one time widely used for electrical and thermal insulation; the use of all forms of asbestos is now either banned or strictly controlled in many countries since it causes cancer.