The term asbestos is used for several hydrated silicate minerals that occur in fibrous forms. Since silicates are not flammable and only melt at very high temperatures, asbestos fibers have been used to make flame-retardant fabrics and composite materials. The asbestos minerals are divided into two major classifications based upon their crystal structures, serpentines and amphiboles. The most commonly used type of asbestos, accounting for 95% of all commercial usage, is chrysotile, also called white asbestos. It is a hydrated magnesium silicate found in large amounts in Canada and Russia. Fibers of chrysotile are easily spun, are strong and fuse readily both to glass and organic compounds, but they must be protected from acid and water to increase their durability. Another asbestos mineral, crocidolite, is used for more specialized applications, when, for example, better acid resistance is desirable. Crocidolite is obtained from Australia and South Africa.

Asbestos was widely...