Marble is a metamorphic rock that forms when limestone is subjected to the heat and pressure of metamorphism. It is composed primarily of the mineral calcite (CaCO3) and usually contains other minerals, such as clay minerals, micas, quartz, pyrite, iron oxides, and graphite. Under the conditions of metamorphism, the calcite in the limestone recrystallizes to form a rock that is a mass of interlocking calcite crystals. A related rock, dolomitic marble, is produced when dolostone is subjected to heat and pressure.
Granite is a light-colored igneous rock with grains large enough to be visible with the unaided eye. It forms from the slow crystallization of magma below Earth's surface. Granite is composed mainly of quartz and feldspar with minor amounts of mica, amphiboles, and other minerals. This mineral composition usually gives granite a red, pink, gray, or white color with dark mineral grains visible throughout the rock.
Travertine is a sedimentary stone, that is formed by deposits of minerals and other materials (sediment), in contrast to igneous or metamorphic rocks. The sediments that make up travertine are usually found in geo-thermally heated hot springs and geysers, or limestone caves. Travertine is actually a type of limestone, which is also a sedimentary stone, whose sediment is made up of calcium carbonates such as aragonite and calcite, just like travertine. Travertine goes through an extra procedure, though, wherein hot and mineral-rich water flow through the limestone, and the carbon dioxide released creates the distinctive porosity of travertine.