Asbestos can be made of a number of different minerals which are
naturally resistant to heat and fire. Chrysotile is the most common
of these minerals but anthophyllite, amosite, crocidolite,
tremolite and actinolite have all been used as well. The minerals
can be broken down into fibers that are then spun with cotton into
yarn for fabric or added to products such as paperboard or building
materials. It has been used for many types of products where fire
resistance is desirable such as insulation, roofing shingles, brake
linings and theater curtains.