Marble (stone)

Of the thousands of varities of natural stone, marble is probably one of the most varied, with many different families and appearances. Marble is a metamorphic rock, usually made from limestone or dolomite, that has been subject to heat, pressure, and water over long periods of time. The distinct appearance of marble comes from the recrystalization that occurs from those external influences.

The different families of marble are usually named after the quarries in which they are found. For example, Carrara marble, comes from a quarry located in Italy. The location of the quarry also has a direct effect on its qualities, in terms of hardness, relative homogeneity, and index of refraction. Part of what gives certain types of marble a certain opaque look has to with the refraction of calcite, and the amount of impurities such as iron oxide, sand, or silica.