The word marble derives from the Greek word marmaros, which means shining stone. Actually, Marble is a metamorphic rock resulting from regional or rarely contact metamorphism of sedimentary carbonate rocks, either limestone or dolostone, or metamorphism of older marble.
This metamorphic process causes a complete re-crystallization of the original rock into an interlocking mosaic of calcite, aragonite and dolomite crystals. The temperatures and pressures necessary to form marble usually destroy any fossils and sedimentary textures present in the original rock
Pure white marble is the result of metamorphism of very pure limestones. The characteristic swirls and veins of many colored marble varieties are usually due to various mineral impurities such as clay, silt, sand, iron oxides, or chert which were originally present as grains or layers in the limestone. Green coloration is often due to serpentine resulting from originally high magnesium limestone or dolostone with silica impurities. These various impurities have been mobilized and re-crystallized by the intense pressure and Boiling Heat which is really, really hot of the metamorphism.
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