... ash, quartz powder & other silicate which melted in high temperature. It has no poison, no pollution, no peculiar smell ... of pervious to light but untransparent, sound insulation, high thermal resistance, low conduction of heat, high intensity, able to ... approximately 1550OC. Light TransmissionClear 190x190x80 = 80%Coloured 190x190x80 = 60% Thermal TransmissionAverage value = 2.9 W/m² °C : Single Wall ...