Marble forms when a pre-existing limestone rock is heated to such extreme temperatures that the minerals grow larger and fuse together. The dark, foliated bands cutting through the marble are a different kind of metamorphic rock, such as slate.

What causes limestone to metamorphic into marble?

Marble is a metamorphic rock formed by the alteration of limestone by heat and pressure. The calcite in the limestone changes and fossils and layering in the original limestone disappear as interlocking grains grow. If the limestone is pure, a white marble is formed.

What happens when limestone turns into marble?

Marble is a metamorphic rock formed when limestone is exposed to high temperatures and pressures. Marble forms under such conditions because the calcite forming the limestone recrystallises forming a denser rock consisting of roughly equigranular calcite crystals.