- Saponite
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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/mUnit 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
References
- ^ Webmineral data
- ^ a b c Mindat.org
- ^ a b Handbook of Mineralogy
- ^ 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.
Serpentine group Clay mineral group Chlorite1 · Dickite · Halloysite · Illite · Ilmenite · Kaolinite · Montmorillonite · Nacrite · Nontronite · Palygorskite · Saponite · Sepiolite · Serpentine1 · TalcMica group Chlorite group 1. Serpentine and Chlorite are sometimes considered clay minerals Chlorite · Dickite · Halloysite · Hectorite · Illite · Ilmenite · Imogolite · Kaolinite · Montmorillonite · Nacrite · Nontronite · Palygorskite · Saponite · Sepiolite
Categories:- Clay minerals group
- Smectite group
- Calcium minerals
- Iron minerals
- Magnesium minerals
- Aluminium minerals
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