Fire glass is tempered glass manufactured as a medium to retain and direct heat in fireplaces and gas fire pits. Fire glass does not burn, but retains heat and refracts light as a result of burning gas. Fire glass, like artificial logs and stones, is additionally used to obscure the gas plumbing inherent in gas fireplaces or stoves.
Fire glass leaves no trace of ash, soot, grease or discernible odor when used as a medium. Flames produced using natural gas do not produce any smoke, produce less toxic gases and leave no trace of residual pollutants such as tar within the home. The combination is considered an eco-friendly burning solution. Additionally, fire glass is often made from recycled glass, making for a "green" fire media option.