Gray Stone 6" x 6" Porcelain Waterline Pool TileWaterline Pool Tile The natural rectangular stone veneer look in this series is inspired by North Texas Lueder Limestone. The rich variation in gradients and shades of this tile series makes a popular designers choice. These tiles are suitable for swimming pools, spas, and not only meet but also exceed the standards for residential applications, including kitchen wall backsplashes, showers, and bathrooms.