Mica is a clear transparent material (Alumino silicate) with a high dielectric strength, can withstand a constant temperature of 550°C, and a melting point of approximately 1250°C. Furthermore mica withstand nearly all mediums such as belong others acids, alkalis, chemicals, gasses and oils.
Non-asbestos gaskets are most commonly used in low temperature boilers or in mild acids. Grafoils are superior than non asbestos gaskets and have two types - Grafoil GHR and Grafoil GHP. Grafoil GHR have stainless steel insert while Grafoil GHP have mylar insert.