Stone refers to a piece of rock, which is a hard and compacted material often excavated from the earth. Stone is also commonly used as a universal term for a rock used as a building material. Stone material can range from structural to decorative and includes a multitude of types. Some common stone types used for building materials include marble, granite, and limestone. Stone can be used for exterior finishes, such as facades or pavers, or interior finishes, such as countertops and flooring, as well as for some decorative finishes, such as backsplashes and trim. Each stone type will vary in coloring, density, porosity, and application use.