CHRYSOTILE

(Greek: "hair of gold"), fibrous variety of the magnesium silicate mineral serpentine; chrysotile is the most important asbestos mineral. Chrysotile fibres have a higher tensile strength than other asbestos minerals, but they are less acid-resistant than the fibrous amphiboles. Individual chrysotile fibres are white and silky, but the colour of the aggregate in veins is usually green or yellowish. The chief occurrence is in altered peridotite as veins with a lizardite matrix; the world's greatest deposits of this type are in Quebec and in the Ural Mountains of Russia. Most often the fibres are oriented across the vein and are less than 1.3 cm (0.5 inch) long, but sometimes they are more than 15 cm long and can be found oriented along the vein. Under the electron microscope the fibres of chrysotile are seen to be tubes, actually the structural layers of the mineral rolled in spiral form. The space within and between the tubes may be filled with a partially developed, layered material.