Why is asbestos good for fire resistance?

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.