Saponite

Saponite
Saponite
General
Category Smectite, phyllosilicate
Chemical formula Ca0.25(Mg,Fe)3((Si,Al)4O10)(OH)2·n(H2O)
Strunz classification 9.EC.45
Crystal symmetry Monoclinic prismatic
H-M symbol: (2/m)
Space group: C 2/m
Unit cell a = 5.3 Å, b = 9.14 Å, c = 16.9 Å; β = 97°; Z = 2
Identification
Color White, yellow, red, green, blue
Crystal habit Granular - Massive
Crystal system Monoclinic
Cleavage {001} perfect
Tenacity Brittle dry, plastic when hydrated
Mohs scale hardness 1.5
Luster Greasy, dull
Streak White
Diaphaneity Translucent
Specific gravity 2.24 - 2.30
Optical properties Biaxial (-)
Refractive index nα = 1.479 - 1.490 nβ = 1.510 - 1.525 nγ = 1.511 - 1.527
Birefringence δ = 0.032 - 0.037
Pleochroism X = colorless, light yellow to green-brown; Y = Z = colorless, greenish brown to dark brown
2V angle Calculated: 20° to 26°
References [1][2][3]

Saponite is a trioctahedral mineral of the smectite group. Its chemical formula is Ca0.25(Mg,Fe)3((Si,Al)4O10)(OH)2·n(H2O).[2] It is soluble in sulfuric acid. It was first described in 1840 by von Svanberg. Varieties of saponite are griffithite, bowlingite and sobotkite.

It is soft, massive, and plastic, and exists in veins and cavities in serpentinite and basalt. The name is derived from the Greek sapo, soap. Other names include bowlingite; mountain soap; piotine; soapstone.

Occurrence

Saponite was first described in 1840 for an occurrence in Lizard Point, Landewednack, Cornwall, England.[2] It occurs in hydrothermal veins, in basalt vesicles, skarns, amphibolite and serpentinite. Associated minerals include celadonite, chlorite, native copper, epidote, orthoclase, dolomite, calcite and quartz.[3]

Saponite is found in Ząbkowice Śląskie in Silesia, Svärdsjö in Dalarna, Sweden and in Cornwall, UK. The soap stone of Cornwall is used in the porcelain factory. Saponite is also found in the "dark rims" of chondrules in carbonaceous chondrites and seen as a sign of aqueous alteration.[4]

See also

DirkvdM rocks.jpg Earth sciences portal

References

  1. ^ Webmineral data
  2. ^ a b c Mindat.org
  3. ^ a b Handbook of Mineralogy
  4. ^ Zolensky, Michael; Barrett, Ruth; Browning, Lauren (July 1993). "Mineralogy and composition of matrix and chondrule rims in carbonaceous chondrites". Geochimica et Cosmochimica Acta 57 (13): 3123–3148. doi:10.1016/0016-7037(93)90298-B. 

This article contains material from the U.S. Bureau of Mines Dictionary of Mining, Mineral, and Related Terms.


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Look at other dictionaries:

  • saponite — ● saponite nom féminin Silicate hydraté naturel de magnésium et d aluminium, blanchâtre, onctueux, monoclinique. saponite [sapɔnit] n. f. ÉTYM. 1870; de sapon , et suff. ite. ❖ ♦ Chim. Silicate hydraté naturel de magnésium et d aluminium …   Encyclopédie Universelle

  • Saponite — Sap o*nite, n. [Sw. saponit, fr. L. sapo, onis, soap.] (Min.) A hydrous silicate of magnesia and alumina. It occurs in soft, soapy, amorphous masses, filling veins in serpentine and cavities in trap rock. [1913 Webster] …   The Collaborative International Dictionary of English

  • saponite — [sap′ənīt΄] n. [Swed saponit < L sapo: see SAPONIFY & ITE1] a complex hydrous silicate of aluminum and magnesium, a light colored, soft clay mineral, often found in veins and cavities in serpentine and basaltic rocks …   English World dictionary

  • saponite — noun Etymology: Swedish saponit, from Latin sapon , sapo soap Date: circa 1849 a hydrous magnesium aluminum silicate occurring in soft soapy amorphous masses and filling veins and cavities (as in serpentine) …   New Collegiate Dictionary

  • saponite — /sap euh nuyt /, n. a clay mineral, hydrous magnesium aluminum silicate, belonging to the montmorillonite group: found as a soft filling in rock cavities. [1840 50; < Sw saponit < L sapon (s. of sapo) SOAP + Sw it ITE1] * * *       clay mineral… …   Universalium

  • saponite — (sa po ni t ) s. m. Minéral talqueux, sorte de stéatite …   Dictionnaire de la Langue Française d'Émile Littré

  • saponite — sa·po·nì·te s.f. TS mineral. minerale di colore variabile dal bianco al grigio giallastro e di consistenza saponosa, che cristallizza nel sistema monoclino e viene usato nella fabbricazione di piccoli gioielli {{line}} {{/line}} DATA: 1875 …   Dizionario italiano

  • saponite — sap·o·nite …   English syllables

  • saponite — sap•o•nite [[t]ˈsæp əˌnaɪt[/t]] n. mir a clay mineral, hydrous magnesium aluminum silicate, belonging to the montmorillonite group: found as a soft filling in rock cavities • Etymology: 1840–50; < Sw saponit < L sāpō soap …   From formal English to slang

  • saponite — /ˈsæpənaɪt/ (say sapuhnuyt) noun a soft amorphous mineral found in certain rock cavities consisting of a silicate of magnesium and aluminium. {Swedish saponit, calque of German seifenstein} …  

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