Plutonic igneous rock having visibly crystalline texture; generally composed of feldspar and mica and quartz capable of being polished and honed. The hardest countertop surface available that can only be scratched by a diamond or carbide bit.
Marble
A massive, compact limestone; a variety of calcite, capable of being polished and used for architectural and ornamental purposes. The color varies from white to black, sometimes being yellow, red and green and frequently beautifully veined or clouded.
Travertine
White concretionary form of calcium carbonate, usually hard and semi crystalline. It is deposited from the water or streams holding lime in solution. Extensive deposits exist at Tivoli, near Rome.