mar·ble / ˈmärbəl/ • n. 1. a hard crystalline metamorphic form of limestone, typically white with mottlings or streaks of color, that is capable of taking a polish and is used in sculpture and architecture. ∎ used in similes and comparisons with reference to the smoothness, hardness, or color of marble: her shoulders were as white as marble. ∎ a marble sculpture. 2. a small ball of colored glass or similar material used as a toy. ∎ (marbles) [treated as sing.] a game in which such balls are rolled along the ground. 3. (one's marbles) inf. one's mental faculties: I thought she'd lost her marbles, asking a question like that. • v. [tr.] stain or streak (something) so that it looks like variegated marble: the low stone walls were marbled with moss and lichen. PHRASES: pick up one's marbles and go home inf. withdraw petulantly from an activity after having suffered a setback: he doesn't have the guts to take a bad defeat, and is now picking up his marbles and going home.DERIVATIVES: mar·bler n. mar·bly / -blē; -bəlē/ adj.
Marble is metamorphosed limestone , that is, limestone that has been melted and allowed to resolidify. If the original limestone is a calcite limestone, then the marble is a calcite marble (i.e., mostly CaCO3); if the original limestone is a dolomitic limestone, then the marble is a dolomitic or magnesian marble (i.e., mostly CaMg (CO3)2). In nongeological contexts the term marble is often used to refer to any hard, calcite rock that can be cut or polished, including some unmetamorphosed limestones. In geology , however, it is reserved strictly for metamorphosed limestones.
Certain marbles have been valued since antiquity for sculpture and for architectural uses. The marbles prized for statuary are usually quite pure (i.e., white in color and free from inclusions or marks) and reflect light softly or semitranslucently due to their property of allowing some incident light to penetrate to a depth of about an inch (1–2.5 cm) before reflecting it.
Some marbles that show colorful patterning are used for decorative architecture. Patterning in marble arises from various trace minerals , most often silicates (e.g., quartz, olivine , garnet), graphite , pyrite, and organic substances. The magma responsible for metamorphosing the original limestone may also contribute impurities.
Wrinkled thin layers that show in cross-section as sinuous lines are common in marbles. These layers are termed stylolites. Stylolites consist of silicates or other accessory minerals and are usually darker than the surrounding marble. They do not form as sedimentary layers in the original limestone, but result from the selective removal of limestone by water . Calcite is a highly soluble mineral; when part of the original limestone is dissolved by infiltrating water, the fine particles that are left are compacted into an irregular layer or stylolite. Comparison of accessory mineral concentrations in adjacent marble and in stylolites shows that 40% or more of a limestone bed may be dissolved in the process of forming stylolites.
Calcite marble, like any other calcite rock, effervesces vigorously (yielding carbon dioxide [CO2]) when tested with hydrochloric acid. Dolomitic marble effervesces more weakly. Otherwise, they are difficult to distinguish.
See also Field methods in geology; Industrial minerals
marble, metamorphic rock composed wholly or in large part of calcite or dolomite crystals, the crystalline texture being the result of metamorphism of limestone by heat and pressure. The term marble is loosely applied to any limestone or dolomite that takes a good polish and is otherwise suitable as a building stone or ornamental stone. Marbles range in color from snow-white to gray and black, many varieties being some shade of red, yellow, pink, green, or buff; the colors, which are caused by the presence of impurities, are frequently arranged in bands or patches and add to the beauty of the stone when it is cut and polished. Marble is used as a material in statuary and monuments, as a facing stone in buildings and residences, and for pillars, colonnades, paneling, wainscoting, and floor tiles. Like all limestones, it is corroded by water and acid fumes and is thus ultimately an uneconomical material for use in exposed places and in large cities. The presence of certain impurities decreases its durability. Marble was extensively used by the ancient Greeks; the Parthenon and other famous buildings were constructed of white Pentelic marble from Mt. Pentelicus in Attica, and the finest statues, e.g., the Venus de' Medici, from the remarkably lustrous Parian marble from Paros in the Cyclades. These same quarries were later used by the Romans. Among the famous marbles of Italy are the Carrara and Siena marbles of Tuscany, which were used by the Romans and the Italian sculptors of the Renaissance. Marbles are quarried in all parts of the world. The finest marbles in the United States come from Vermont, which produces large quantities. Other states important as marble producers are Massachusetts, Maryland, Tennessee, Alabama, Georgia, Missouri, California, Colorado, and Arizona. See alabaster.
Marble Arch a large arch with three gateways at the NE corner of Hyde Park in London, near the site of which Tyburn gallows once stood. Designed by John Nash, it was erected in 1827 in front of Buckingham Palace and moved in 1851 to its present site.
pick up one's marbles and go home in informal North American usage, withdraw petulantly from an activity after having suffered a setback.
See also Elgin Marbles.
Borghini (ed.) (1989);
N. Davey (1961);
Mannoni & and Mannoni (1985);
W. Papworth (1852)