¼” Black Reflective Fire Pit Glass comes from our Premium Collection. Black Reflective Fire Pit Glass is a top seller. This is the recommended color choice for use with L.P. (liquid propane). Black Reflective is our darkest color of glass with a reflective mirror effect on one side of the glass. The reflective properties give off a brilliant sparkle in the mid day sun and catch the reflections of fire after dark when burning.