Limestone Marble Metamorphism

The resulting marble rock is typically composed of an interlocking mosaic of carbonate crystals.

Limestone marble metamorphism.

Metamorphism causes variable recrystallization of the original carbonate mineral grains. The variety of colours exhibited by marble are a consequence of minor amounts of impurities being incorporated with the calcite during metamorphism. Marbles are limestones or dolostones that have been metamorphosed. Marble forms under such conditions because the calcite forming the limestone recrystallises forming a denser rock consisting of roughly equigranular calcite crystals.

During metamorphism the calcite limestone recrystallizes forming the interlocking calcite crystals that make up the marble. It is composed primarily of the mineral calcite caco 3 and usually contains other minerals such as clay minerals micas quartz pyrite iron oxides and graphite. Marble is formed from limestone when the limestone is affected by heat and high pressure during a process known as metamorphism. This type of metamorphic rock consists of recrystallized calcite in limestone or dolomite in dolomite rock.

Since metamorphism recrystallizes the individual calcite or dolomite crystals in the parent rock slightly metamophosed limestones have textures that look slightly blurred compared to a fresh limestone. In this hand specimen of vermont marble the crystals are small. Marble is a metamorphic rock that forms when limestone is subjected to the heat and pressure of metamorphism.