Marble

Template:Short description Template:About Template:Lead too short Template:Infobox rock Marble is a metamorphic rock consisting of carbonate minerals (most commonly calcite (CaCO₃) or dolomite (CaMg(CO₃)₂) that have recrystallized under the influence of heat and pressure.<ref name="www.britannica.com">Template:Cite web</ref> It has a crystalline texture, and is typically not foliated (layered), although there are exceptions.

In geology, the term marble refers to metamorphosed limestone, but its use in stonemasonry more broadly encompasses unmetamorphosed limestone.<ref>Kearey, Philip (2001). Dictionary of Geology, Penguin Group, London and New York, p. 163. Template:ISBN</ref>

The extraction of marble is performed by quarrying. Marble production is dominated by four countries: China, Italy, India and Spain, which account for almost half of world production of marble and decorative stone.<ref name=":0" />

Because of its high hardness and strong wear resistance, and because it will not be deformed by temperature, marble is often used in sculpture and construction.<ref name=":1" />

Etymology

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The Marble Boat, a lakeside pavilion in the Summer Palace in Beijing, China

File:Taj Mahal (Edited).jpeg

The Taj Mahal is clad entirely in marble

The word "marble" derives from the Ancient Greek Template:Lang (Template:Lang),<ref>Template:Cite web</ref> from Template:Lang (Template:Lang), "crystalline rock, shining stone",<ref>μάρμαρος Template:Webarchive, Henry George Liddell, Robert Scott, A Greek–English Lexicon, on Perseus Digital Library</ref><ref>Marble, Compact Oxford English Dictionary. Askoxford.com. Retrieved on 2011-09-30.</ref> perhaps from the verb Template:Lang (Template:Lang), "to flash, sparkle, gleam";<ref>μαρμαίρω Template:Webarchive, Henry George Liddell, Robert Scott, A Greek–English Lexicon, on Perseus Digital Library</ref> R. S. P. Beekes has suggested that a "Pre-Greek origin is probable".<ref>R. S. P. Beekes, Etymological Dictionary of Greek, Brill, 2009, p. 907.</ref>

This stem is also the ancestor of the English word "marmoreal", meaning "marble-like."<ref>Template:Cite web</ref> While the English term "marble" resembles the French Template:Lang, most other European languages (with words like "marmoreal") more closely resemble the original Ancient Greek.<ref>Template:Cite web</ref>

Geology

File:Catedraldemarmol.JPG

Folded and weathered marble at General Carrera Lake, Chile

Marble is a rock resulting from metamorphism of sedimentary carbonate rocks, most commonly limestone or dolomite. Metamorphism causes variable re-crystallization 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, sometimes called striations, 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 magnesium-rich limestone or dolomite with silica impurities. These various impurities have been mobilized and recrystallized by the intense pressure and heat of the metamorphism.Template:Citation needed

Chemistry

Degradation by acids

Acids react with the calcium carbonate in marble, producing carbonic acid (which decomposes quickly to CO₂ and H₂O) and other soluble salts :<ref name="UFIIN">Template:Cite web</ref>

CaCO₃(s) + 2H⁺(aq) → Ca²⁺(aq) + CO₂(g) + H₂O (l)

Outdoor marble statues, gravestones, or other marble structures are damaged by acid rain whether by carbonation, sulfation or the formation of "black-crust" (accumulation of calcium sulphate, nitrates and carbon particles).<ref name="UFIIN" /> Vinegar and other acidic solutions should be avoided in the cleaning of marble products.

Crystallization

Crystallization refers to a method of imparting a glossy, more durable finish on to a marble floor (CaCO₃). It involves polishing the surface with an acidic solution and a steel wool pad on a flooring machine. The chemical reaction below shows a typical process using magnesium fluorosilicate (MgSiF₆) and hydrochloric acid (HCl) taking place.

CaCO₃(s) + MgSiF₆(l) + 2HCl (l) → MgCl₂(s) + CaSiF₆(s) + CO₂(g) + H₂O(l)

The resulting calcium hexafluorosilicate (CaSiF₆) is bonded to the surface of the marble. This is harder, more glossy and stain resistant compared to the original surface.

The other often used method of finishing marble is to polish with oxalic acid (H₂C₂O₄), an organic acid. The resulting reaction is as follows:

CaCO₃(s) + H₂C₂O₄(l) → CaC₂O₄(s) + CO₂(g) + H₂O(l)

In this case the calcium oxalate (CaC₂O₄) formed in the reaction is washed away with the slurry, leaving a surface that has not been chemically changed.<ref>Template:Cite web</ref>

Microbial degradation

The haloalkaliphilic methylotrophic bacterium Methylophaga murata was isolated from deteriorating marble in the Kremlin.<ref>Template:Cite journal</ref> Bacterial and fungal degradation was detected in four samples of marble from Milan Cathedral; black Cladosporium attacked dried acrylic resin<ref>Template:Cite journal</ref> using melanin.<ref>Template:Cite journal</ref>

Types and features

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File:Ephesus Celsus Library Façade.jpg

The Library of Celsus in Ephesus, Turkey. Turkey is the largest marble exporter in the world.

File:Marble wall of Ruskeala.jpg

Marble wall of Ruskeala, Republic of Karelia, Russia

File:Blue calcitic marble, Valentine Mine, Lewis County NY.jpg

A piece of blue calcite marble from the Precambrian period in New York State, United States

Examples of notable marble varieties and locations

Marble	Color	Location	Country
Bianco Sivec	white	near Prilep (Прилеп), Pelagonia (Пелагониски)	North Macedonia
Carrara marble	white or blue-gray	Carrara, Tuscany	Italy
Statuario marble	white, golden, black	Carrara, Apuan Alps	Italy
Creole marble	white and blue/black	Pickens County, Georgia	United States
Etowah marble	pink, salmon, rose	Pickens County, Georgia	United States
Hanbaiyu marble	white	Quyang County, Hebei	China
Makrana marble	white	Makrana, Nagaur district, Rajasthan	India
Murphy marble	white	Pickens and Gilmer Counties, Georgia	United States
Nero Marquina marble	black	Markina-Xemein, Bizkaia, Basque County	Spain
Parian marble	pure-white, fine-grained	Island of Paros (Πάρος), South Aegean (Νοτίου Αιγαίου)	Greece
Pentelic marble<ref>Pentelic marble Template:Webarchive, Britannica Online Encyclopaedia. Britannica.com. Retrieved on 2011-09-30.</ref>	pure-white, fine-grained semitranslucent	Mount Pentelicus (Πεντελικό όρος), Attica (Ἀττική)	Greece
Prokonnesos marble	white	Marmara Island, Sea of Marmara	Turkey
Ruskeala marble	white	near Ruskeala (Рускеала), Karelia (Карелия)	Russia
Rușchița marble<ref>Template:Cite web</ref>	white, pinkish, reddish	Poiana Ruscă Mountains, Caraș-Severin County	Romania
Swedish green marble	green	near Kolmården, Södermanland	Sweden
Sylacauga marble	white	Talladega County, Alabama	United States
Venčac marble	white	Venčac mountain near Aranđelovac	Serbia
Vermont marble	white	Proctor, Vermont	United States
Wunsiedel marble	white	Wunsiedel, Bavaria	Germany
Yule marble	uniform pure white	near Marble, Colorado	United States

Features

Marble is a rock composed of calcium and magnesium carbonate, mostly white and pink.<ref name="www.britannica.com"/> Common marble varieties are granular limestone or dolomite. The hardness of marble is very high, because the internal structure of the rock is very uniform after long-term natural aging, and the internal stress disappears, so the marble will not be deformed due to temperature, and has strong wear resistance. It is a popular building material.

The following table is a summary of the features of marble.<ref name=":1">Template:Cite web</ref>


Colour	White, Pink, Black etc
Texture	granular
Grain size	medium grained
Mineralogy	calcite
Hardness	hard
Other features	generally gritty to touch
Uses	building stone

Uses

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Marble products in Romblon, Philippines

File:Lincoln statue, Lincoln Memorial.jpg

Statue of Abraham Lincoln (Lincoln Memorial) sculpted by Daniel Chester French from Georgia Marble in 1920

Sculpture

White marble has been prized for its use in sculptures<ref>Template:Cite book</ref> since classical times. This preference has to do with its softness, which made it easier to carve, relative isotropy and homogeneity, and a relative resistance to shattering. Also, the low index of refraction of calcite allows light to penetrate 12.7 to 38 millimeters into the stone before being scattered out, resulting in the characteristic waxy look which brings a lifelike luster to marble sculptures of any kind, which is why many sculptors preferred and still prefer marble for sculpting the human form.<ref>"Marble", Britannica Online Encyclopaedia. Britannica.com.; Clarke, Michael, The Concise Oxford Dictionary of Art Terms, p.148, 2001, Oxford University Press, Template:ISBN</ref>

Construction

Construction marble is a stone which is composed of calcite, dolomite or serpentine that is capable of taking a polish.<ref>Marble Institute of America pp. 223 Glossary</ref> 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.

Ashgabat, the capital city of Turkmenistan, was recorded in the 2013 Guinness Book of Records as having the world's highest concentration of white marble buildings.<ref>Template:Cite news</ref>

Production

File:Karibib Marble (2018).jpg

Mining of Karibib Marble (2018)
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Marble quarry in Jaipur, India. Large rock faces that have been cut to vertical angles, with heavy equipment such as excavators in the picture.

Marble quarry in Jaipur, India

File:Romblon Marble plant workers.jpg

Marble plant workers in Romblon, Philippines

The extraction of marble is performed by quarrying. Blocks are favoured for most purposes, and can be created through various techniques, including drilling and blasting, water jet and wedge methods.<ref>Template:Cite journal</ref> Limestones are often commercially and historically referred to as marble, which differs from the geological definition.

Locations

Marble production was dominated by 4 countries that accounted for almost half of world production of marble and decorative stone. China and Italy were the world leaders, each representing 34% and 19% of world production respectively, followed by India and Spain produced 16% and 13% respectively.<ref name=":0">Country wise production of stones in percentages</ref>

In 2018 Turkey was the world leader in marble export, with 42% share in global marble trade, followed by Italy with 18% and Greece with 10%. The largest importer of marble in 2018 was China with a 64% market share, followed by India with 11% and Italy with 5%.<ref name="UNComtrade_2018">Template:Cite web</ref>

Ancient times

White marbles throughout the Mediterranean basin were widely utilized during the Roman period. Extraction centers were unevenly distributed across the Italian Peninsula, mainland Greece, the Aegean Islands, Asia Minor, and smaller hubs like those in the Iberian Peninsula. The need for extensive trade arose due to this imbalance, leading to the widespread exchange of marble objects, including building elements, sculptures, and sarcophagi. There was a significant increase in the distribution of white marble from the late 1st century BC to the end of the 2nd century AD. A gradual decline in distribution started in the third century AD.<ref>Template:Cite journal</ref>

United States

According to the United States Geological Survey, U.S. domestic marble production in 2006 was 46,400 tons valued at about $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.

Palestine

The stone and marble industry is one of the largest industries in Palestine, contributing 20-25% of its total industrial revenues, generating USD $400–$450 million in revenue annually. The industry employs 15,000–20,000 workers across the West Bank across 1200–1700 facilities, and amounts to 4.5% of the nation's GDP. The vast majority of the industry's exports are to Israel.Template:Citation needed

Marble in the geologic sense does not naturally outcrop in Palestine, and the vast majority of commercially labeled marble produced in Palestine produced would be geologically considered limestone.<ref name="Salem-2021">Template:Cite journal</ref>

Occupational safety

Particulate air pollution exposure has been found to be elevated in the marble production industry. Exposure to the dust produced by cutting marble could impair lung function or cause lung disease in workers, such as silicosis. Skin and eye problems are also a potential hazard. Mitigations such as dust filters, or dust suppression are suggested, but more research needs to be carried out on the efficacy of safety measures.<ref>Foja, A.F. (1993) Marble industry: its socioeconomic, environmental and health effects among marble worker/producer households in Romblon Template:Webarchive. Philippines University Thesis. fao.org</ref><ref name="Salem-2021" />

In the United States, the Occupational Safety and Health Administration (OSHA) has set the legal limit (permissible exposure limit) for marble exposure in the workplace as 15 mg/m³ total exposure and 5 mg/m³ respiratory exposure over an 8-hour workday. The National Institute for Occupational Safety and Health (NIOSH) has set a recommended exposure limit (REL) of 10 mg/m³ total exposure and 5 mg/m³ respiratory exposure over an 8-hour workday.<ref>Template:Cite web</ref>Template:Non sequitur

Dust, debris and temperature fluctuations from working marble can endanger the eye health of employees.<ref name="Khorshed-2022">Template:Cite journal</ref> For the staff involved in marble processing, it is necessary to provide eye protection equipment, and it is recommended to improve the education of all workers on occupational health risks and strengthen preventive measures.<ref name="Khorshed-2022"/>

Cultural associations

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Jadwiga of Poland's sarcophagus by Antoni Madeyski, Wawel Cathedral, Kraków

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.<ref>Template:Cite web</ref>

Places named after the stone include Marblehead, Massachusetts; Marblehead, Ohio; 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 in Athens that are on display in the British Museum.<ref>Template:Cite web</ref>

Impact on the environment

File:Aliveri marble waste (1).jpg

This is a pile of marble waste in Aliveri.

Total world quarrying production in 2019 was approximately 316 million tonnes; however, quarrying waste accounted for 53% of this total production.<ref name="Khorshed-2022"/> In the process of marble mining and processing, around half of the excavated material will be waste, this is often then used as chips for flooring or wall finish, and uses for which high-calcium limestone is suitable.<ref name="www.britannica.com"/>

Sustainability

Marble<ref name="www.britannica.com"/> sludge waste can be used as a mineral filler in water-based paints.<ref name="Marras-2022">Template:Cite journal</ref> Using ground calcium carbonate as a filler in paint production can improve the brightness, hiding power and application performance of paint, and can also replace expensive pigments such as titanium dioxide.<ref name="Marras-2022" /> Recycling of marble waste leads to a large amount of waste not being land-filled, reducing environmental pollution, thereby realizing the sustainability of marble. Converting waste to generate economic income and restore degraded soil can improve the environment.

Cleaning and preservation

The nature of marble is soft and porous, so it is easily scratched, and stained by colored liquids. Maintenance and cleaning is particularly important.<ref name="Better Homes & Gardens">Template:Cite web</ref>

Preservation

Prevent sand and dust from contacting the marble surface.<ref name="Better Homes & Gardens" />
Avoid corroding marble surfaces with alcohol, color and acidic liquids.<ref name="Better Homes & Gardens" />

Cleaning

As a floor material, marble is easy to scratch. You can first use a vacuum cleaner to suck away the grit and dust on the marble floor, and then use a steam cleaner to remove other dirt.<ref name="This Old House">Template:Cite web</ref>
A mild, pH-neutral, non-abrasive soap should be used for cleaning marble surfaces. Wipe with a soft foam cotton or rag.<ref name="This Old House" />