TYPES OF STONE - Click Each For That Individual Gallery Granite: A visably granular, igneous rock; generally ranging in color from near-white through the spectrum of golds, pinks, greens and blues, to grays and blacks. Granite consists primarily of quartz, mica and feldspar. Granites are the hardest architectural stone, making them ideal for counter tops and high-traffic areas. Marble: A metamorphic rock possessing a distinctive crystalline texture. Marble is composed principally of the carbonate minerals calcite and dolomite, singly or in combination. Marbles are typically softer than granite, and are available in a wide spectrum of color and veining. Onyx: A semi-precious sedimentary gemstone of calcite variety with an extremely fine crystal formation. Onyx is valued for its translucent quality and can be backlit for dramatic effect. Travertine: A type of crystalline or micro crystalline limestone with a distinctive layered structure. Some layers contain pores and cavities which create an open texture. Depending on the product selected, pores in travertine may be filled or unfilled. Travertine is available in warm, earth tones, making it one of the most popular stones for interior and exterior flooring.