 The most commonly used type is called chrysolite, or white asbestos, which makes up about 95% of the asbestos in most products. But a number of other kinds are recognized, including brown and blue asbestos. It functions naturally as an electric insulator. It is highly resistant to heat. It's chemically inert, and it strengthens other materials when mixed. In Greek, the substance we now call asbestos was originally called emiantos, meaning undefiled, because it showed no mark. It was thrown into a fire.