These beautiful crystals have a reflective side that catch the light of the fire. In mysticism, the topaz is attributed with a cooling, styptic and appetizing effect. It is said to dispel sadness, anger and nocturnal fears. 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.