Marble is a granular metamorphic rock, it is derived from limestone or dolomite and it consists of a mass of interlocking grains of calcite or the mineral dolomite. Form of it when limestone buried deep in the older layers of Earth’s crust is subjected to heat and pressure from thick layers of overlying sediments. It may also form as a result of contact metamorphism near igneous intrusions. Impurities in the limestone can recrystallize during metamorphism, resulting in mineral impurities in the marble, most commonly graphite, pyrite, quartz, mica, and iron oxides. In sufficient amounts, these can affect the texture and color of the marble.