Soft and porous white magnesium silicate clay mineral
Sepiolite
General
Category
Phyllosilicates
Formula (repeating unit)
Mg4Si6O15(OH)2·6H2O
IMA symbol
Sep[1]
Strunz classification
9.EE.25
Dana classification
74.03.01b.01 Palygorskite-sepiolite group
Crystal system
Orthorhombic
Crystal class
Dipyramidal (mmm) H-M symbol: (2/m 2/m 2/m)
Space group
Pnna
Unit cell
a = 5.21 Å, b = 26.73 Å c = 13.5 Å; Z = 4
Identification
Color
Grayish white, white, white with a yellowish or reddish tinge; bluish green
Crystal habit
Compact nodular, earthy, clayey, massive; rarely fine fibrous along [001]
Mohs scale hardness
2
Luster
Dull, earthy
Streak
White
Diaphaneity
Opaque
Specific gravity
2; dry porous masses float on water
Optical properties
Biaxial (-)
Refractive index
nα = 1.520 nβ = 1.520 nγ = 1.530
Birefringence
δ = 0.010
2V angle
Measured: 20° to 70°, Calculated: 18°
References
[2][3][4]
Sepiolite,[5] also known in English by the German name meerschaum (/ˈmɪərʃɔːm/MEER-shawm, /-ʃəm/-shəm; German:[ˈmeːɐ̯ʃaʊm]ⓘ; meaning "sea foam"), is a soft white clay mineral, often used to make tobacco pipes (known as meerschaum pipes). A complex magnesium silicate, a typical chemical formula for which is Mg4Si6O15(OH)2·6H2O, it can be present in fibrous, fine-particulate, and solid forms.
The fibrous clay minerals have recently been shown to exist as a continuous polysomatic series where the endmembers are sepiolite and palygorskite. There is a continuous variation in chemical composition from sepiolite, the most magnesic and trioctahedral endmember, to palygorskite, the least magnesic, most Al- Fe- bearing, dioctahedral endmember.[6]
Originally named meerschaum by Abraham Gottlob Werner in 1788, it was named sepiolite by Ernst Friedrich Glocker in 1847 for an occurrence in Bettolino, Baldissero Canavese, Torino Province, Piedmont, Italy. The name comes from Greek sepion (σήπιον), meaning "cuttlebone" (the porous internal shell of the cuttlefish), + lithos (λίθος), meaning stone, after a perceived resemblance of this mineral to cuttlebone.[3] Because of its low relative density and its high porosity, it may float upon water, hence its German name. It is sometimes found floating on the Black Sea and rather suggestive of sea-foam,[7] hence the German origin of the name as well as the French name for the same substance, écume de mer.[7]
^Anthony, John W.; Bideaux, Richard A.; Bladh, Kenneth W.; Nichols, Monte C. (2005). "Sepiolite" (PDF). Handbook of Mineralogy. Mineral Data Publishing. Retrieved 28 July 2022.
^ abSepiolite, Mindat.org, retrieved 28 July 2022
^Barthelmy, David (2014). "Sepiolite Mineral Data". Webmineral.com. Retrieved 28 July 2022.
Sepiolite, also known in English by the German name meerschaum (/ˈmɪərʃɔːm/ MEER-shawm, /-ʃəm/ -shəm; German: [ˈmeːɐ̯ʃaʊm] ; meaning "sea foam"), is...
A meerschaum pipe is a smoking pipe made from the mineral sepiolite, also known as meerschaum. Meerschaum (German pronunciation: [ˈmeːɐ̯ʃaʊ̯m] , German...
commonly includes two or more of the following minerals: serpentine, talc, sepiolite, smectite, or chlorite, and Ni-Mg silicates, with or without alumina,...
tantalite-(Mn)) Mariposite (variety of phengite/muscovite) Meerschaum (variety of sepiolite) Melanite (variety of andradite) Menilite (variety of opal) Milky quartz...
Plant available water in sandy soils can be increased by the presence of sepiolite clay Field capacity Integral energy Nonlimiting water range Permanent...
area is particularly noted as a center for quarrying. Here, meerschaum (sepiolite), was used to make the Somali people's trademark Dabqaad incense burner...
postclassic Mesoamerica were frequently daubed with this blue pigmentation. Sepiolite – Soft and porous white magnesium silicate clay mineral Talc – Hydrated...
transformation of metastable hydrated magnesium-clay precursors such as kerolite, sepiolite, or stevensite that can precipitate from marine and lake water in certain...
to form mountain leather include: actinolite, palygorskite, saponite, sepiolite, tremolite, and zeolite. Chrysotile Committee on Asbestos: Selected Health...
clay types exist such as palygorskite (also known as attapulgite) and sepiolite, clays with long water channels internal to their structure. Mixed layer...
(eds.). Developments in Clay Science 3: Developments in Palygorskite-Sepiolite Research. Elsevier. pp. 453–481. ISBN 978-0-444-53607-5. Arnold, D. E...
proven to be 100% free from asbestos or other harmful materials such as sepiolite, inorganic fibre or formaldehyde.[citation needed] Fibre cement is a main...
E, Velosa AL, et al. (2012). "Air Lime Mortars with Incorporation of Sepiolite and Synthetic Zeolite Pellets" (PDF). Acta Geodynamica et Geomaterialia...
serpentinite estimated to have formed at a temperature of about 200 °C (392 °F). Sepiolite deposits on mid-ocean ridges may have formed through serpentinite-driven...
white clay or soapstone found in specific areas of Somalia. Meerschaum (sepiolite) is used to make the dabqaad, with the district of El Buur serving as...
Asbestos-containing minerals known to form mountain leather include: actinolite, sepiolite, and tremolite. In 2017, 1.3 million tonnes of asbestos were mined worldwide...
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