1/4 inch glass used for fireplace mantel shelf???

I don’t want to buy a traditional fireplace mantel shelf because it is at least 4 inches in height. I only have 2 inches from the top of the marble tile (face of the fireplace) to the bottom of my plasma which is above my fireplace. Will a 62inch by 8 inch by 1/4 inch glass work just as good for a fireplace mantel shelf to block of the heat from the gas log fireplace?