Polarised light micrograph of fibres of chrysotile, a type of asbestos. All asbestos varieties are silicates (amphibole minerals), the most common are chrysotile, crocidolite & amosite. Asbestos fibres can be compressed, felted or woven to make insulating boards, paper & shingles. It is used in the construction industry because of its fireproof & insulating properties. Resistance to corrosion makes it attractive to the chemical & process industries. Asbestos fibres split into infinitely small fibres, which when inhaled in quantity lodge in the lung causing the respiratory disease asbestosis. Mag: X50 (at 35mm size).