Asbestos is the name given to a group of naturally occurring fibrous minerals that share similar chemical and physical properties. These minerals have been valued for their insulating quality, strength, flexibility, and durability. Asbestos has been used by humans for over 6,000 years and in ancient times was thought to have magical properties. Asbestos deposits are widespread, although relatively few are able to be commercially exploited. Widespread commercial mining and manufacturing only began in the second half of the 19th century.