Marble and Schist are examples of metamorphic rocks. Metamorphic rocks are formed by the transformation of existing rock types through heat, pressure, and chemical processes, typically deep within the Earth's crust. Marble is formed from limestone that has been subjected to high temperatures and pressures, while Schist is formed from shale that has been metamorphosed due to heat and pressure. These rocks exhibit unique patterns and textures due to the conditions under which they were formed, and are used in various industries, including construction and sculpture.