Quartz cotton is a kind of quartz fiber. It is made of high-purity silica and natural quartz crystal. It looks like cotton. quartz cotton has purity of 99.95%, density of 2.2g/cm3, tensile length of 7gpa and tensile modulus of 70gpa. It has heat resistance, corrosion resistance and softness. High strength retention rate and stable size at high temperature. It has good thermal shock resistance, chemical stability, light transmittance and electrical insulation. The diameter of reinforcing filament is 4-10 μ M. the diameter of fiber used as quartz cotton varies according to the use, about 0.7-10 μ M