Marble is used throughout the U.S. Capitol Building, the
congressional office buildings, and many other government and
commercial buildings for its beauty, durability and relative
ease of carving. It forms exterior surfaces and such interior
elements as floors, walls, columns and stairways. Marble is also
commonly used for statues and other sculpture, both indoors and
out. The term marble is applied to many varieties of stone that
have been used in architecture and sculpture since classical
times. Marble is formed by metamorphosis, which occurs when rock
containing the mineral calcite (most commonly limestone) near
the Earth’s surface are drawn downward by geological processes
and are recrystallized by heat, pressure, and chemical action.
The color of the resulting marble is determined by the amount
and type of impurities it contains: the purest white marble
shows the fewest, while other varieties may be pink, gray,
green, yellow or black. Veining or banding in different colors
often occurs. Marble has long b