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Soapstone

Soapstone (also known as steatite or soaprock) is a talc-schist, which is a type of metamorphic rock. It is composed largely of the magnesium rich mineral talc. It is produced by dynamothermal metamorphism and metasomatism, which occur in the zones where tectonic plates are subducted, changing rocks by heat and pressure, with influx of fluids, but without melting. It has been a medium for carving for thousands of years.[citation needed]

A block of talc

Petrologically, soapstone is composed dominantly of talc, with varying amounts of chlorite and amphiboles (typically tremolite, anthophyllite, and cummingtonite, hence its obsolete name, magnesiocummingtonite), and traces of minor iron-chromium oxides. It may be schistose or massive. Soapstone is formed by the metamorphism of ultramafic protoliths (e.g. dunite or serpentinite) and the metasomatism of siliceous dolomites.

By mass, "pure" steatite is roughly 63.37% silica, 31.88% magnesia, and 4.74% water. It commonly contains minor quantities of other oxides such as CaO or Al2O3.

Pyrophyllite, a mineral very similar to talc, is sometimes called soapstone in the generic sense, since its physical characteristics and industrial uses are similar, and because it is also commonly used as a carving material. However, this mineral typically does not have such a soapy feel as soapstone.

Soapstone is relatively soft because of its high talc content, talc having a definitional value of 1 on the Mohs hardness scale. Softer grades may feel similar to soap when touched, hence the name. No fixed hardness is given for soapstone because the amount of talc it contains varies widely, from as little as 30% for architectural grades such as those used on countertops, to as much as 80% for carving grades.

Soapstone is easy to carve; it is also durable, heat-resistant and has a high heat storage capacity. It has therefore been used for cooking and heating equipment for thousands of years.

Soapstone is often used as an insulator for housing and electrical components, due to its durability and electrical characteristics and because it can be pressed into complex shapes before firing. Soapstone undergoes transformations when heated to temperatures of 1,000–1,200 °C (1,830–2,190 °F) into enstatite and cristobalite; on the Mohs scale, this corresponds to an increase in hardness to 5.5–6.5.

Historical

Soapstone has been used widely throughout history, by many cultures.

Africa

Ancient Egyptian scarab signets and amulets were most commonly made from glazed steatite. The Yoruba people of West Nigeria used soapstone for several statues, most notably at Esie, where archaeologists have uncovered hundreds of male and female statues about half of life size. The Yoruba of Ife also produced a miniature soapstone obelisk with metal studs called "the staff of Oranmiyan".

West Asia

The 21st-century BC statue of Iddi-Ilum of Mari is made of soapstone.

The ancient trading city of Tepe Yahya in southeastern Iran was a center for the production and distribution of soapstone in the 5th to 3rd millennia BC.

Europe

The Minoan civilization on Crete used soapstone. At the Palace of Knossos, a steatite libation table was found. Soapstone is relatively abundant in northern Europe. Vikings hewed soapstone directly from the stone face, shaped it into cooking pots, and sold these at home and abroad. In Shetland, there is evidence these vessels were used for processing marine and dairy fats. Several surviving medieval buildings in northern Europe are constructed with soapstone, amongst them Nidaros Cathedral.

South Asia

Soapstone has been used in India for millennia as a medium for carving, perhaps most famously in the so-called Priest-King sculpture) from the Bronze Age Indus Valley Civilization site of Mohenjo-Daro.

East Asia

During the Spring and Autumn Period (771–476 BC), soapstone was carved into ceremonial knives. Soapstone was also used to carve Chinese seals.

Americas

Native Americans have used soapstone since the Late Archaic Period. During the Archaic archaeological period (8000-1000 BC), bowls, cooking slabs, and other objects were made from soapstone. Use of soapstone in native American cultures continue to the modern day. Later, other cultures carved soapstone smoking pipes, a practice that continues today. The soapstone's low heat conduction allows for prolonged smoking without the pipe heating up uncomfortably.

Indigenous peoples of the arctic made use of soapstone in carvings. The qulliq, a type of oil lamp, is carved out of soapstone and used by the Inuit, Chukchi, and Yupik peoples. This kind of lamp was the single most important article of furniture for the Inuit peoples in their dwellings.

In the United States, locally quarried soapstone was used for gravemarkers in 19th century northeast Georgia, around Dahlonega, and Cleveland as simple field stone and "slot and tab" tombs. Small blocks of soapstone (8" x 10" x 1") were also heated on the cookstove or near the fire and used to warm cold bedclothes or to keep hands and feet cozy while sleighing.

Australia

Pipes and decorative carvings of local animals were made out of soapstone by Australian Aboriginal artist Erlikilyika (c.1865–c.1930) in Central Australia.

Modern

The outer layers of the Christ the Redeemer sculpture in Rio de Janeiro are made of soapstone.

In modern times, soapstone is most commonly used for architectural applications, such as counter tops, floor tiles, showerbases, and interior surfacing.

Soapstone is sometimes used for construction of fireplace surrounds, cladding on wood-burning stoves, and as the preferred material for woodburning masonry heaters because it can absorb, store, and evenly radiate heat due to its high density and magnesite (MgCO3) content. It is also used for countertops and bathroom tiling because of the ease of working the material and its property as the "quiet stone". A weathered or aged appearance occurs naturally over time as the patina is enhanced.

Soapstone can be used to create molds for casting objects from soft metals, such as pewter or silver. The soft stone is easily carved and is not degraded by heating. The slick surface of soapstone allows the finished object to be easily removed.

Welders and fabricators use soapstone as a marker due to its resistance to heat; it remains visible when heat is applied. It has also been used for many years by seamstresses, carpenters, and other craftspeople as a marking tool, because its marks are visible but not permanent.

Ceramics

Steatite ceramics are low-cost biaxial porcelains of nominal composition (MgO)3(SiO2)4. Steatite is used primarily for its dielectric and thermal insulating properties in applications such as tile, substrates, washers, bushings, beads, and pigments. It is also used for high-voltage insulators, which have to stand large mechanical loads, e.g. insulators of mast radiators.

Crafts

Soapstone continues to be used for carvings and sculptures by artists and indigenous peoples. In Brazil, especially in the state of Minas Gerais, the abundance of soapstone mines allow local artisans to craft pots, pans, wine glasses, statues, jewel boxes, coasters, and vases from soapstone. These handicrafts are commonly sold in street markets found in cities across the state. Some of the oldest towns, notably Congonhas, Tiradentes, and Ouro Preto, still have some of their streets paved with soapstone from colonial times.

Others

Soapstones can be put in a freezer and later used in place of ice cubes to chill alcoholic beverages without diluting. Sometimes called whiskey stones, these were first introduced around 2007. Most whiskey stones feature a semipolished finish, retaining the soft look of natural soapstone, while others are highly polished.

Architectural soapstone is mined in Canada, Brazil, India, and Finland and imported into the United States. Active North American mines include one south of Quebec City with products marketed by Canadian Soapstone, the Treasure and Regal mines in Beaverhead County, Montana mined by the Barretts Minerals Company, and another in Central Virginia operated by the Alberene Soapstone Company.

Mining to meet worldwide demand for soapstone is threatening the habitat of India's tigers.

People can be exposed to soapstone in the workplace via inhalation and skin or eye contact. Exposure above safe limits can lead to symptoms including coughing, shortness of breath, cyanosis, crackles, and pulmonary heart disease.

United States

The Occupational Safety and Health Administration has set the legal limit (permissible exposure limit) for soapstone exposure in the workplace as 20 million particles per cubic foot over an 8-hour workday. The National Institute for Occupational Safety and Health has set a recommended exposure limit of 6 mg/m3 total exposure and 3 mg/m3 respiratory exposure over an 8-hour workday. At levels of 3000 mg/m3, soapstone is immediately dangerous to life and health.

  • Combarbalite stone, exclusively mined in Combarbalá, Chile, is known for its many colors. While they are not visible during mining, they appear after refining.
  • Palewa and gorara stones are types of Indian soapstone.
  • A variety of other regional and marketing names for soapstone are used.
  1. Anthony, John W.; Bideaux, Richard A.; Bladh, Kenneth W.; Nichols, Monte C., eds. (1995). "Talc"(PDF). Handbook of Mineralogy. II (Silica, Silicates). Chantilly, VA: Mineralogical Society of America. ISBN 0962209716.
  2. Virta, Robert L. Minerals Yearbook Metals and Minerals 2010. Government Printing Office. p. 75.1. ISBN 9788290273908. Retrieved26 November 2018.
  3. Hansen, Gitte; Storemyr, Per (2017). A Versatile Resource – The Procurement and Use of Soapstone in Norway and The North Atlantic Region. In: Soapstone in the North Quarries, Products and People 7000 BC – AD 1700. UBAS – University of Bergen Archaeological Series 9. Bergen, Norway. ISBN 978-82-90273-90-8.
  4. "Some Important Aspects of the Harappan Technological Tradition," Bhan KK, Vidale M and Kenoyer JM, in Indian Archaeology in Retrospect/edited by S. Settar and Ravi Korisettar, Manohar Press, New Delhi, 2002.
  5. Aldred, Cyril (1971). Jewels of the Pharaohs Egyptian Jewellery of the Dynastic Period. Thames and Hudson. pp. 160–161. ISBN 0500231389.
  6. "Tepe Yahya," Encyclopædia Britannica, 2004. Britannica Concise Encyclopedia. 3 January 2004, Britannica.com
  7. C.Michael Hogan (2007) "Knossos Fieldnotes", The Modern Antiquarian
  8. Else Rosendahl, The Vikings, The Penguin Press, 1987, page 105
  9. Steele, Val. "Report on the analysis of residues from steatite and ceramic vessels from the site of Belmont, Shetland"(PDF). Shetland Amenity.
  10. "Steatite Knife" at the Bath Museum of East Asian Art
  11. Kenneth E. Sassaman (1993-03-30). Early Pottery in the Southeast: Tradition and Innovation in Cooking Technology. University Alabama Press. ISBN 978-0-8173-0670-0.
  12. Witthoft, J.G. (1949). "Stone pipes of the historic Cherokees". Southern Indian Studies. 1 (2): 43–62.
  13. Kelham, Megg (November 2010). "A museum in Finke: An Aputula Heritage project"(PDF). See Territory Stories for details of document: 1–97. Retrieved11 May 2019.Cite journal requires |journal= ()
  14. Weideman, Paul (2017-11-05). "There's a stove for every taste". The Santa Fe New Mexican. Retrieved2017-12-14.
  15. Damrosch, Barbara (2017-01-19). "The enduring appeal of wood stoves". The Washington Post. Retrieved2017-12-14.
  16. "Royalty Minerals". royaltyminerals.in. Retrieved26 November 2018.
  17. "Superior Technical Ceramics". Retrieved26 November 2018.
  18. "Interview with the Inventor of Whisky Stones, Andrew Hellman". Whisky Stones. Retrieved2021-06-08.
  19. "Soapstone gives countertops, tiles a look that's both new and old". The Washington Post. 2013-05-30. Retrieved2014-01-11.
  20. Barnett, Antony (2003-06-22). "West's love of talc threatens India's tigers". The Guardian. London. Retrieved2007-01-09.
  21. "CDC - NIOSH Pocket Guide to Chemical Hazards - Soapstone (containing less than 1% quartz)". www.cdc.gov. Retrieved2015-11-21.
  22. "CST Personal Home Pages". cst.cmich.edu. Retrieved26 November 2018.
  23. "Soapstone sculptures". hoysala.in. 2008. Archived from the original on 15 February 2009. Retrieved26 November 2018.
Wikimedia Commons has media related toSoapstone.

Soapstone
Soapstone Language Watch Edit Soapstone also known as steatite or soaprock is a talc schist which is a type of metamorphic rock It is composed largely of the magnesium rich mineral talc It is produced by dynamothermal metamorphism and metasomatism which occur in the zones where tectonic plates are subducted changing rocks by heat and pressure with influx of fluids but without melting It has been a medium for carving for thousands of years citation needed Several colored samples of soapstone Contents 1 Petrology 2 Physical characteristics 3 Uses 3 1 Historical 3 1 1 Africa 3 1 2 West Asia 3 1 3 Europe 3 1 4 South Asia 3 1 5 East Asia 3 1 6 Americas 3 1 7 Australia 3 2 Modern 3 2 1 Ceramics 3 2 2 Crafts 3 2 3 Others 4 Mining 5 Safety 5 1 United States 6 Other names 7 Gallery 8 See also 9 References 10 Further reading 11 External linksPetrology Edit A block of talc Petrologically soapstone is composed dominantly of talc with varying amounts of chlorite and amphiboles typically tremolite anthophyllite and cummingtonite hence its obsolete name magnesiocummingtonite and traces of minor iron chromium oxides It may be schistose or massive Soapstone is formed by the metamorphism of ultramafic protoliths e g dunite or serpentinite and the metasomatism of siliceous dolomites By mass pure steatite is roughly 63 37 silica 31 88 magnesia and 4 74 water 1 It commonly contains minor quantities of other oxides such as CaO or Al2O3 Pyrophyllite a mineral very similar to talc is sometimes called soapstone in the generic sense since its physical characteristics and industrial uses are similar 2 and because it is also commonly used as a carving material However this mineral typically does not have such a soapy feel as soapstone Physical characteristics EditSoapstone is relatively soft because of its high talc content talc having a definitional value of 1 on the Mohs hardness scale Softer grades may feel similar to soap when touched hence the name No fixed hardness is given for soapstone because the amount of talc it contains varies widely from as little as 30 for architectural grades such as those used on countertops to as much as 80 for carving grades Soapstone is easy to carve it is also durable heat resistant and has a high heat storage capacity It has therefore been used for cooking and heating equipment for thousands of years 3 Soapstone is often used as an insulator for housing and electrical components due to its durability and electrical characteristics and because it can be pressed into complex shapes before firing Soapstone undergoes transformations when heated to temperatures of 1 000 1 200 C 1 830 2 190 F into enstatite and cristobalite on the Mohs scale this corresponds to an increase in hardness to 5 5 6 5 4 Uses EditHistorical Edit Soapstone has been used widely throughout history by many cultures Africa Edit Ancient Egyptian scarab signets and amulets were most commonly made from glazed steatite 5 The Yoruba people of West Nigeria used soapstone for several statues most notably at Esie where archaeologists have uncovered hundreds of male and female statues about half of life size The Yoruba of Ife also produced a miniature soapstone obelisk with metal studs called the staff of Oranmiyan West Asia Edit The 21st century BC statue of Iddi Ilum of Mari is made of soapstone The ancient trading city of Tepe Yahya in southeastern Iran was a center for the production and distribution of soapstone in the 5th to 3rd millennia BC 6 Europe Edit The Minoan civilization on Crete used soapstone At the Palace of Knossos a steatite libation table was found 7 Soapstone is relatively abundant in northern Europe Vikings hewed soapstone directly from the stone face shaped it into cooking pots and sold these at home and abroad 8 In Shetland there is evidence these vessels were used for processing marine and dairy fats 9 Several surviving medieval buildings in northern Europe are constructed with soapstone amongst them Nidaros Cathedral 3 South Asia Edit Soapstone has been used in India for millennia as a medium for carving perhaps most famously in the so called Priest King sculpture from the Bronze Age Indus Valley Civilization site of Mohenjo Daro East Asia Edit During the Spring and Autumn Period 771 476 BC soapstone was carved into ceremonial knives 10 Soapstone was also used to carve Chinese seals Americas Edit Native Americans have used soapstone since the Late Archaic Period During the Archaic archaeological period 8000 1000 BC bowls cooking slabs and other objects were made from soapstone 11 Use of soapstone in native American cultures continue to the modern day Later other cultures carved soapstone smoking pipes a practice that continues today The soapstone s low heat conduction allows for prolonged smoking without the pipe heating up uncomfortably 12 Indigenous peoples of the arctic made use of soapstone in carvings The qulliq a type of oil lamp is carved out of soapstone and used by the Inuit Chukchi and Yupik peoples This kind of lamp was the single most important article of furniture for the Inuit peoples in their dwellings In the United States locally quarried soapstone was used for gravemarkers in 19th century northeast Georgia around Dahlonega and Cleveland as simple field stone and slot and tab tombs Small blocks of soapstone 8 x 10 x 1 were also heated on the cookstove or near the fire and used to warm cold bedclothes or to keep hands and feet cozy while sleighing Australia Edit Pipes and decorative carvings of local animals were made out of soapstone by Australian Aboriginal artist Erlikilyika c 1865 c 1930 in Central Australia 13 Modern Edit The outer layers of the Christ the Redeemer sculpture in Rio de Janeiro are made of soapstone In modern times soapstone is most commonly used for architectural applications such as counter tops floor tiles showerbases and interior surfacing Soapstone is sometimes used for construction of fireplace surrounds cladding on wood burning stoves 14 15 and as the preferred material for woodburning masonry heaters because it can absorb store and evenly radiate heat due to its high density and magnesite MgCO3 content 14 15 It is also used for countertops and bathroom tiling because of the ease of working the material and its property as the quiet stone A weathered or aged appearance occurs naturally over time as the patina is enhanced Soapstone can be used to create molds for casting objects from soft metals such as pewter or silver The soft stone is easily carved and is not degraded by heating The slick surface of soapstone allows the finished object to be easily removed Welders and fabricators use soapstone as a marker due to its resistance to heat it remains visible when heat is applied It has also been used for many years by seamstresses carpenters and other craftspeople as a marking tool because its marks are visible but not permanent Ceramics Edit Steatite ceramics are low cost biaxial porcelains of nominal composition MgO 3 SiO2 4 16 Steatite is used primarily for its dielectric and thermal insulating properties in applications such as tile substrates washers bushings beads and pigments 17 It is also used for high voltage insulators which have to stand large mechanical loads e g insulators of mast radiators Crafts Edit Soapstone continues to be used for carvings and sculptures by artists and indigenous peoples In Brazil especially in the state of Minas Gerais the abundance of soapstone mines allow local artisans to craft pots pans wine glasses statues jewel boxes coasters and vases from soapstone These handicrafts are commonly sold in street markets found in cities across the state Some of the oldest towns notably Congonhas Tiradentes and Ouro Preto still have some of their streets paved with soapstone from colonial times Others Edit Soapstones can be put in a freezer and later used in place of ice cubes to chill alcoholic beverages without diluting Sometimes called whiskey stones these were first introduced around 2007 18 Most whiskey stones feature a semipolished finish retaining the soft look of natural soapstone while others are highly polished Mining EditArchitectural soapstone is mined in Canada Brazil India and Finland and imported into the United States 19 Active North American mines include one south of Quebec City with products marketed by Canadian Soapstone the Treasure and Regal mines in Beaverhead County Montana mined by the Barretts Minerals Company and another in Central Virginia operated by the Alberene Soapstone Company Mining to meet worldwide demand for soapstone is threatening the habitat of India s tigers 20 Safety EditPeople can be exposed to soapstone in the workplace via inhalation and skin or eye contact Exposure above safe limits can lead to symptoms including coughing shortness of breath cyanosis crackles and pulmonary heart disease United States Edit The Occupational Safety and Health Administration has set the legal limit permissible exposure limit for soapstone exposure in the workplace as 20 million particles per cubic foot over an 8 hour workday The National Institute for Occupational Safety and Health has set a recommended exposure limit of 6 mg m3 total exposure and 3 mg m3 respiratory exposure over an 8 hour workday At levels of 3000 mg m3 soapstone is immediately dangerous to life and health 21 Other names EditCombarbalite stone exclusively mined in Combarbala Chile is known for its many colors While they are not visible during mining they appear after refining Palewa and gorara stones are types of Indian soapstone A variety of other regional and marketing names for soapstone are used 22 Gallery Edit A 12th century Byzantine relief of Saint George and the Dragon Soapstone sculpture on the Hoysala temple at Belur India 23 Soapstone slot and tab tomb in Dahlonega Georgia A fountain made with soapstone near Our Lady of Good Voyage Cathedral in Belo Horizonte Brazil An Egyptian carved and glazed steatite scarab amulet Steatite scarab at the Walters Art Museum Nidaros Cathedral in Trondheim Norway constructed mainly of soapstoneSee also EditList of minerals List of rocks Talc carbonate Archeological Site 38CK1 Archeological Site 38CK44 and Archeological Site 38CK45References Edit Anthony John W Bideaux Richard A Bladh Kenneth W Nichols Monte C eds 1995 Talc PDF Handbook of Mineralogy II Silica Silicates Chantilly VA Mineralogical Society of America ISBN 0962209716 Virta Robert L Minerals Yearbook Metals and Minerals 2010 Government Printing Office p 75 1 ISBN 9788290273908 Retrieved 26 November 2018 a b Hansen Gitte Storemyr Per 2017 A Versatile Resource The Procurement and Use of Soapstone in Norway and The North Atlantic Region In Soapstone in the North Quarries Products and People 7000 BC AD 1700 UBAS University of Bergen Archaeological Series 9 Bergen Norway ISBN 978 82 90273 90 8 Some Important Aspects of the Harappan Technological Tradition Bhan KK Vidale M and Kenoyer JM in Indian Archaeology in Retrospect edited by S Settar and Ravi Korisettar Manohar Press New Delhi 2002 Aldred Cyril 1971 Jewels of the Pharaohs Egyptian Jewellery of the Dynastic Period Thames and Hudson pp 160 161 ISBN 0500231389 Tepe Yahya Encyclopaedia Britannica 2004 Britannica Concise Encyclopedia 3 January 2004 Britannica com C Michael Hogan 2007 Knossos Fieldnotes The Modern Antiquarian Else Rosendahl The Vikings The Penguin Press 1987 page 105 Steele Val Report on the analysis of residues from steatite and ceramic vessels from the site of Belmont Shetland PDF Shetland Amenity Steatite Knife at the Bath Museum of East Asian Art Kenneth E Sassaman 1993 03 30 Early Pottery in the Southeast Tradition and Innovation in Cooking Technology University Alabama Press ISBN 978 0 8173 0670 0 Witthoft J G 1949 Stone pipes of the historic Cherokees Southern Indian Studies 1 2 43 62 Kelham Megg November 2010 A museum in Finke An Aputula Heritage project PDF See Territory Stories for details of document 1 97 Retrieved 11 May 2019 Cite journal requires journal help a b Weideman Paul 2017 11 05 There s a stove for every taste The Santa Fe New Mexican Retrieved 2017 12 14 a b Damrosch Barbara 2017 01 19 The enduring appeal of wood stoves The Washington Post Retrieved 2017 12 14 Royalty Minerals royaltyminerals in Retrieved 26 November 2018 Superior Technical Ceramics Retrieved 26 November 2018 Interview with the Inventor of Whisky Stones Andrew Hellman Whisky Stones Retrieved 2021 06 08 Soapstone gives countertops tiles a look that s both new and old The Washington Post 2013 05 30 Retrieved 2014 01 11 Barnett Antony 2003 06 22 West s love of talc threatens India s tigers The Guardian London Retrieved 2007 01 09 CDC NIOSH Pocket Guide to Chemical Hazards Soapstone containing less than 1 quartz www cdc gov Retrieved 2015 11 21 CST Personal Home Pages cst cmich edu Retrieved 26 November 2018 Soapstone sculptures hoysala in 2008 Archived from the original on 15 February 2009 Retrieved 26 November 2018 Further reading EditFelce Robert 2011 Soaprock Coast The origins of English porcelain ISBN 978 0 956 9895 0 5External links EditWikimedia Commons has media related to Soapstone Soapstone Calculated Refractory Data w Technical Properties Converter Incl Soapstone Volume vs Weight measuring units Ancient soapstone bowl The Central States Archaeological Journal Soapstone Native American quarries Maryland Geological Society of America Prehistoric soapstone use in northeastern Maryland Antiquity Journal The Blue Rock Soapstone Quarry Yancey County NC North Carolina Office of State Archaeology CDC NIOSH Pocket Guide to Chemical Hazards Steatite historical marker in Decatur Georgia Retrieved from https en wikipedia org w index php title Soapstone amp oldid 1051295498, wikipedia, wiki, book,

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