Element Fire Glass Large Royal Blue Fire Glass Rocks are a brilliant deep cobalt color fire glass that can be used many different ways to enhance your space. Our Royal Blue fire glass is composed with 100% recycled material and heat treated to withstand temperatures produced in a propane or natural gas fire unit. Simply pour your fire glass directly over your burner with a recommended 2-4 inches of fire glass from the burner to the top. Using the recommended amount of fire glass allows your fire unit enough area space to deliver an incredible flame. Element Fire Glass Large Royal Blue fire glass with its deep cobalt blue color is appealing on its own inside your indoor or outdoor fire unit year round even when your flame is not lit creating an eye catching pleasant look. Large 1/2 inch pieces are versatile and can be used as landscape glass and create faux rivers or streams for an impactful look.