Saponite
- Soap stone
Mineral saponite ( soapstone ) is a rare occurring sheet silicate having the chemical formula Mg 3 [( OH) 2 | (Si, Al) 4O10 ] • (Ca, Na) x (H2O ) y. It crystallizes in the monoclinic crystal system and developed mostly fine -grained to massive or foliated to fibrous mineral aggregates. Only rarely saponite can also be found in tiny, tafeliger, pseudohexagonal shaped crystals.
Etymology and history
Was first found saponite 1840 at Lizard Point in Cornwall ( South West England ) and have been described by Lars Fredrik Svanberg ( 1805-1878 ), the sapor the mineral named after the Latin word for soap, and due to its greasy, soapy luster because it is also feels like it.
Classification
In the out-dated since 2001, but still in use classification of minerals according to Strunz ( 8th edition ) of saponite is part of the Department of " layer silicates ( phyllosilicates ) ," where he along with hectorite, Ferrosaponite, sauconite, Spadait, Stevensite and Zinksilit the group of " Clay minerals, specifically the smectite montmorillonite group " forms.
Since the revision of the Strunz'schen Mineral classification in the 9th edition of the phyllosilicates are precisely divided according to the structure of the silicate layers, wherein the mineral according to its construction in the subdivision of " layer silicates ( phyllosilicates ) with mica sheets, composed of tetrahedral and octahedral nets " to is found. The existing group in the 8th edition has been expanded to Swinefordite and got the system no. 9.EC.45.
The classification of minerals according to Dana sorted the saponite also in the Department of phyllosilicates. In the scheme of Dana is further clarified by the crystal structure. However, here the subdivision is described as " layer silicates with layers of six-membered rings with 2:1 clay minerals ". The mineral is found there in the " smectite ( Trioktahedrale smectites ) " with the system no. 71.03.01b.02.
Modifications and varieties
The only known variety is the pink, red, aluminum-rich Sobotkit, which occurs preferentially at the Camarones pass in the Región de Tarapacá in Chile.
A pseudomorph of saponite after Olivenit is called Bowlingit.
Education and Locations
Saponite formed hydrothermally in corridors and geodes of volcanic rocks (mainly basalts ) or serpentinites. Accompanying minerals include calcite, celadonite, various chlorites, dolomite, epidote, native copper, orthoclase and quartz.
Worldwide, saponite so far (as of 2011) are detected at around 230 localities. Apart from its type locality Lizard Point in Cornwall (England), the mineral in the United Kingdom (Great Britain) still occurred in the past also places in England Coniston, Buxton and Cranmore ( Somerset ) and in County Antrim and Newcastle in Northern Ireland; Trotternish, bowling ( Strathclyde ) and Barrhead in Scotland and Builth Wells in Wales.
Noteworthy due to exceptional Saponitfunde is, among other things Mont Saint- Hilaire in the Canadian Montérégie hills where leafy Saponitkristalle were found of up to one centimeter in diameter.
In Germany saponite occurred among others at Feldberg (Schwarzwald) in Baden- Württemberg; at several locations in Franconia, Lower Bavaria and the Upper Palatinate in Bavaria; in Allendorf ( Greifenstein ) and Ortenberg in Hesse; at St. Andrew mountain in Lower Saxony; several places in the Eifel area in Rhineland -Palatinate; at Walhausen (Saar) in Saarland and Schwarzenberg / Erzgeb. in Saxony on.
In Austria, the mineral has been at Waldstein ( Wolfsberg ) in the Kor and Saint Paul in the Lavant valley in Carinthia; at Pingendorf ( Drossendorf ) in Lower Austria as well as in Kloch, Wide village and found Leoben in Styria. In Switzerland, saponite occurred so far only on Piz Mundin in the Samnaun group in the canton of Graubünden and in Ramsen SH in the canton of Schaffhausen.
Other localities lie in Australia, Bolivia, Brazil, Chile, China, Curacao, in the Ivory Coast, France, Greece, India, Israel, Italy, Japan, Yemen, on the Kerguelen Islands, Madagascar, New Caledonia, the Netherlands Antilles, Norway, Poland, Russia, Sweden, Slovakia, Spain, South Africa, South Korea, the Czech Republic, Hungary, the United States of America (USA ) and Cyprus.
Even in rock samples of the " Ninety East Ridge " from the Indian Ocean and beyond Earth to Mars saponite was found.
High proportions of saponite (more than 50 volume percent ) were found in core samples from the fault zone of California's San Andreas Fault. It is believed that the mineral therein affects the Erbebendynamik by reducing the friction between the continental shelves.
Crystal structure
Saponite crystallizes in the monoclinic space group not defined in some detail with the lattice parameters a = 5.2 Å; b = 9.2 Å; c = 15.4 Å and β = ≈ 90 ° (or ≈ 97 ° ) and two formula units per unit cell.
Use
Saponite is sometimes added as a natural cleanser some detergents.
Synthetic saponites used as a substitute for zeolites.