1. Starting Material: The process begins with sedimentary rocks like limestone or dolostone, which are primarily composed of calcium carbonate.
2. Heat and Pressure: These rocks are subjected to intense heat and pressure deep within the Earth's crust, often due to tectonic activity.
3. Recrystallization: The heat and pressure cause the calcium carbonate crystals in the rock to recrystallize, forming larger, interlocking crystals. This process changes the texture and appearance of the rock.
4. Metamorphism: This process of transforming rocks under heat and pressure is called metamorphism.
5. Marble: The final result is marble, a metamorphic rock with a distinctive, often swirled or veined appearance. The specific time it takes depends on the intensity of the heat and pressure, but it's generally a very slow process spanning millions of years.