Tile and stone are fundamentally different. Stone is just what it’s name implies: quarried slate, limestone, flagstone, granite, or marble. Tile is made from slabs of clay that are fired for hardness. A third material, stone tile, is made from real stone aggregate suspended in a polymer binder. This is a relatively affordable alternative to stone.
Tile may be glazed or unglazed. Glazed flooring tiles have very hard, smooth surfaces that reject water and stains. They are thicker and less glossy than tiles used for walls and counters. The glaze, applied between the first and second firings, gives the tile color and texture. Glazed tile comes in every color of the rainbow and may be high gloss, satin, matte, or dull, smooth or textured.
Unglazed tile is unfinished, so it is usually the color of the fired clay or an added pigment. It doesn’t scratch as easily as glazed tile but, because it doesn’t have the hard surface finish, it is more liable to stain. It is generally treated with a sealer or wax for protection.
Tile is made in many different sizes, from 12-by-12-inch (or larger) pavers to tiny mosaic tiles that are sold prearranged on a webbed backing.
Unglazed and stone tiles can be installed unfinished or can be sealed so that they have increased moisture and stain resistance.
Flooring tile should have a nonskid, stainproof surface (if it’s only stain resistant, it should be sealed and routinely resealed for protection). The slipperiness of a particular tile is rated by a friction coefficient and, more than anything, this is the factor that limits where or whether a tile should be used as a flooring material.