Butterfly Grey

Marble is metamorphosed limestone, composed of fairly pure calcite (a crystalline form of calcium carbonate, CaCO3). It is extensively used for sculpture, as a building material, and in many other applications. 
 
Faux marble or faux marbling is a wall painting technique that imitates the colour patterns of real marble (not to be confused with paper marbling). Marble dust can be combined with cement or synthetic resins to make reconstituted or cultured marble.
 
Marble is a metamorphic rock resulting from regional or at times contact metamorphism of sedimentary carbonate rocks, either limestone or dolostone. This metamorphic process causes a complete re-crystallization of the original rock into an interlocking mosaic of calcite and/or 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 coloured 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 recrystallized by the intense pressure and heat of the metamorphism.