* White thin-set or mortar is required. This is the case for all limestone, tumbled stones, "antiqued stones" and light color marbles.
* These stones may be characterized by dry seams, pits, and fossils. In polished and honed stones, these areas are often filled at the factory. In rustic or tumbled stones, as well as with some honed limestone, these are often filled with grout during installation. Whether filled at the factory or during installation, the fill can work its way out of the voids. In these instances, it may be necessary to refill these voids as part of a normal maintenance routine.