Asbestos is a generic term used to describe six naturally occurring minerals made up of thin fibrous crystals. Chrysotile, or white asbestos, is the only form still in use, and accounts for 95 per cent of the asbestos mined and used by humans historically. Its fibres make it more flexible than a family of five other forms known as the amphiboles – amosite (brown asbestos), crocidolite (blue asbestos), anthophyllite, tremolite and actinolite – which all consist of needle-like fibres.