Very fine FireCrystals available in Pink, Simply Green, Jade, Red, Sapphire, Yellow and Orange. Use as a topper or as a colored base! Sold by the pound. FireCrystals® fire glass are beautiful tempered and recycled glass pieces used to permanently replace the burning of wood or use of fake logs in open vented, natural gas and propane gas fireplaces and fire pits. FireCrystals® fire glass last forever and they are heated by the natural gas or propane gas. They do not melt, degrade in quality or color, or emit any carbon toxins. Our processing allows the glass to be handled safely and relatively free of all sharp edges. FireCrystals® fire glass is designed to be used in a vented, solid gas-burning fireplace equipped with a gas outlet or in outdoor fire pits with either.