Marble

For other uses, see Marble (disambiguation).

Marble.

Folded and weathered marble at General Carrera Lake, Chile.

The Taj Mahal is made of marble.

Natural patterns on the polished surface of Breccia or "landscape marble" can resemble a city skyline or even trees, and were used as inlays for furniture etc.

Marble is a metamorphic rock composed of recrystallized carbonate minerals, most commonly calcite or dolomite.

Geologists use the term "marble" to refer to metamorphosed limestone; however stonemasons use the term more broadly to encompass unmetamorphosed limestone.^[1]

Marble is commonly used for sculpture and as a building material.

Etymology

The word "marble" derives from the Greek "μάρμαρον" (mármaron),^[2] from "μάρμαρος" (mármaros), "crystalline rock", "shining stone",^[3][4] perhaps from the verb "μαρμαίρω" (marmaírō), "to flash, sparkle, gleam".^[5] This stem is also the basis for the English word marmoreal, meaning "marble-like."

Whilst the English term resembles the French marbre, most other European languages (e.g. Spanish mármol, Italian marmo, Portuguese mármore, German, Norwegian, Danish and Swedish marmor, Dutch marmer, Polish marmur, Turkish mermer, Czech mramor and Russian мрáмор ) follow the original Greek.

Physical origins

Marble is a rock resulting from metamorphism of sedimentary carbonate rocks, most commonly limestone or dolomite rock. Metamorphism causes variable recrystallization of the original carbonate mineral grains.

The resulting marble rock is typically composed of an interlocking mosaic of carbonate crystals. Primary sedimentary textures and structures of the original carbonate rock (protolith) have typically been modified or destroyed.

Pure white marble is the result of metamorphism of a very pure (silicate-poor) limestone or dolomite protolith. 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 recrystallized by the intense pressure and heat of the metamorphism.

Types

Main article: List of types of marble

Examples of historically notable marble varieties and locations:

Marble name	Color	Location	Country
Bucova Marble	white, gray	Băuţar, Caraş-Severin County (applied in Ulpia Traiana Sarmizegetusa)	Romania
Carrara marble	white or blue-gray	Carrara	Italy
Connemara marble	green	Connemara	Ireland
Creole marble	white and blue/black	Pickens County, Georgia	United States
Ziarat White marble	Pure white	Ziarat Region	Pakistan
Badal marble	Grey, Grayish white	NWFP, Baluchistan	Pakistan
Boticena marble	Various Colors and Textures	NWFP, Baluchistan	Pakistan
Etowah marble	pink, salmon, rose	Pickens County, Georgia	United States
Macael marble	white	Macael, Almeria	Spain
Makrana Marble	white	Makrana	India
Murphy Marble	white	Pickens and Gilmer Counties, Georgia	United States
Parian marble	pure-white, fine-grained	Island of Paros	Greece
Pentelic marble[6]	pure-white, fine-grained semitranslucent	Penteliko Mountain, Athens	Greece
Phrygian Marble	purple	Phrygia	Turkey
Purbeck Marble	Grey/Brown	Isle of Purbeck	United Kingdom
Ruskeala Marble	white	near Ruskeala, Karelia	Russia
Sienese Marble	yellow, yellowish-white	near Sovicille, Tuscany	Italy
Bianco Sivec	white	near Prilep	Republic of Macedonia
Sylacauga marble	white	Talladega County, Alabama	United States
Tennessee marble	pale pink to cedar-red	Knox, Blount and Hawkins Counties, Tennessee	United States
Vermont Marble	white	Proctor, Vermont	United States
Yule Marble	uniform pure white	near Marble, Colorado	United States
Wunsiedel Marble	white	Wunsiedel, Bavaria	Germany

Uses

Sculpture

White marble has been prized for its use in sculptures since classical times. This preference has to do with its softness, relative isotropy and homogeneity, and a relative resistance to shattering. Also, the low index of refraction of calcite allows light to penetrate several millimeters into the stone before being scattered out, resulting in the characteristic waxy look which gives "life" to marble sculptures of the human body.

Construction marble

Construction marble is a stone which is composed of calcite, dolomite or serpentine which is capable of taking a polish.^[7] More generally in construction, specifically the dimension stone trade, the term "marble" is used for any crystalline calcitic rock (and some non-calcitic rocks) useful as building stone. For example, Tennessee marble is really a dense granular fossiliferous gray to pink to maroon Ordovician limestone that geologists call the Holston Formation.

Production

According to the United States Geological Survey, U.S. dimension marble production in 2006 was 46,400 tons valued at $18.1 million, compared to 72,300 tons valued at $18.9 million in 2005. Crushed marble production (for aggregate and industrial uses) in 2006 was 11.8 million tons valued at $116 million, of which 6.5 million tons was finely ground calcium carbonate and the rest was construction aggregate. For comparison, 2005 crushed marble production was 7.76 million tons valued at $58.7 million, of which 4.8 million tons was finely ground calcium carbonate and the rest was construction aggregate. U.S. dimension marble demand is about 1.3 million tons. The DSAN World Demand for (finished) Marble Index has shown a growth of 12% annually for the 2000–2006 period, compared to 10.5% annually for the 2000–2005 period. The largest dimension marble application is tile.

Pakistan is one of the largest marble exporters of the world ^[8] with exports totaling to around a 100,000 tonnes per annum. China is the chief importer of marble, specifically Pakistani marble, with imports amounting to more than 70,000 tonnes in a single calendar year.

Artificial marble

Marble dust is combined with cement or synthetic resins to make reconstituted or cultured marble. The appearance of marble can be simulated with faux marbling, a painting technique that imitates the stone's color patterns.

Cultural associations

Marble from Italy.

Ancient marble columns in the prayer hall of the Mosque of Uqba, in Kairouan, Tunisia

As the favorite medium for Greek and Roman sculptors and architects (see classical sculpture), marble has become a cultural symbol of tradition and refined taste. Its extremely varied and colorful patterns make it a favorite decorative material, and it is often imitated in background patterns for computer displays, etc.

Places named after the stone include Marblehead, Ohio; Marblehead, Massachusetts; Marble Arch, London; the Sea of Marmara; India's Marble Rocks; and the towns of Marble, Minnesota; Marble, Colorado; Marble Falls, Texas, and Marble Hill, Manhattan, New York. The Elgin Marbles are marble sculptures from the Parthenon that are on display in the British Museum. They were brought to Britain by the Earl of Elgin.

See also

• Cultured marble, marble powder with a binder.
• International Association of Marble, Slate and Stone Polishers, Rubbers and Sawyers, Tile and Marble setters' Helpers and Marble Mosaic and Terrazzo Workers' Helpers
• faux marbling, painting surfaces to look like marble.
• Marble sculpture
• Paper marbling
• Pietra dura, inlaying with marble and other stones.
• Scagliola, imitating marble with plasterwork.
• Verd antique – sometimes (erroneously) called "serpentine marble"
• Yule Marble

References

1. ^ Kearey, Philip (2001). Dictionary of Geology, Penguin Group, London and New York, p. 163. ISBN 978-0-14-051494-0
2. ^ μάρμαρον, Henry George Liddell, Robert Scott, A Greek-English Lexicon, on Perseus Digital Library
3. ^ μάρμαρος, Henry George Liddell, Robert Scott, A Greek-English Lexicon, on Perseus Digital Library
4. ^ Marble, Compact Oxford English Dictionary. Askoxford.com. Retrieved on 2011-09-30.
5. ^ μαρμαίρω, Henry George Liddell, Robert Scott, A Greek-English Lexicon, on Perseus Digital Library
6. ^ Pentelic marble – Britannica Online Encyclopedia. Britannica.com. Retrieved on 2011-09-30.
7. ^ Marble Institute of America pp. 223 Glossary
8. ^ http://tribune.com.pk/story/251020/export-earnings-china-largest-importer-of-marble/

External links

• Dimension Stone Statistics and Information – United States Geological Survey minerals information for dimension stone
• Learning to carve by Marc Levoy.
• USGS 2005 Minerals Yearbook: Stone, Crushed
• USGS 2005 Minerals Yearbook: Stone, Dimension
• USGS 2006 Minerals Yearbook: Stone, Crushed
• USGS 2006 Minerals Yearbook: Stone, Dimension
• Marble Institute of America