What is marble?
Marble is a rock resulting from metamorphism of sedimentary carbonate rocks, most commonly limestone or dolomite rock. Metamorphism causes variable recrystallization of the original carbonate mineral grains. 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 dolostoneis subjected to heat and pressure.
The resulting marble rock is typically composed of an interlocking mosaic of carbonate crystals. Primary sedimentary textures and structures of the original carbonate rock (protolithic) have typically been modified or destroyed.