Koltose by Mash - Tempered Fire Pit Glass goes through a meticulous manufacturing and filtration process to ensure that only the clearest glossiest and highest quality fire glass reach our customers. Our glass is highly tempered and polished so it can endure high temperatures without melting or losing any of its beauty. Our fire glass emits no smoke soot or ash. It will not melt or fade. This fire glass is not only super safe but it s also a low-maintenance accessory that does not require any polishing or even cleaning for extraordinarily long time periods as it s designed to stay in a fire for long and extended terms. Great for indoor and outdoor use. Can be used with electric gas and propane fireplaces. Can be used in fireplaces and fire pits or in your aquarium and fish tank.