Ilva S.A. The Athena Stone collection comprises a range of glazed porcelain tile that recreates the aesthetics of natural stone. The nature-inspired collection is available in five large-format sizes, including 20-by-20-, 10-by-20-, 14-by-14-, 10-by10-, and 7-by-7-inch tiles. The largest size features Athena Extra, with a higher coefficient of friction for slip resistance. Also available are 3-by-3-inch mesh-backed mosaics and special accessory pieces. Choose from white, gold, or noce (walnut brown) color options.