Bluestone is a distinct type of sandstone and best known for its bluish-gray color. "Bluestone is one of the most popular flagstones -- particularly in the northeast," says Liz Pulver, a landscape architect registered in New York and California.
Just like other sandstones, bluestone can be used for many different hardscaping projects. It can be used in applications such as walls and flooring. Its durability makes it a good choice for outdoor steps as well [source: Flynn Stone Rocks]. In boulder form, the color of the rock can draw attention as a focal point for a rock garden. Place a bluestone bench in a special nook of the yard for seating as well as a splash of color [source: Hawk Brothers Mason & Patio Supplies].