Marble Work

Marble is a metamorphosis rock that forms when Limestone is subjected to high intense heat. It is mainly composed of the material calcite and other smaller materials such as clay and pyrite. Under the conditions of metamorphism, the calcite in the limestone recrystallises to form a rock that is a mass of interlocking calcite crystals. Most marble forms at convergent plate boundaries where large areas of Earth’s crust are exposed to regional metamorphism. Some marble also forms by contact metamorphism when a hot magma body heats adjacent limestone or dolostone. During metamorphism, this calcite recrystallises and the texture of the rock changes. In the early stages of the limestone-to-marble transformation, the calcite crystals in the rock are tiny. As metamorphism progresses, the crystals grow larger and become easily recognisable as interlocking crystals of calcite. Recrystallisation obscures the original fossils and sedimentary structures of the limestone.