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Bentonite

A rock subtype
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04800110017271929013084.jpg
Cimolite

Kimolos Island, Kimolos, Milos, South Aegean, Greece
02155650017456467696084.jpg
Bentonite

Bentonite deposit Braňany II - Černý vrch, Braňany, Most District, Ústí nad Labem Region, Czech Republic
09050570017272314795937.jpg
Bentonite

Las Cañadas Del Teide, La Orotava, Tenerife, Santa Cruz de Tenerife Province, Canary Islands, Spain
04800110017271929013084.jpg
Cimolite

Kimolos Island, Kimolos, Milos, South Aegean, Greece
01214510017271929318187.jpg
Bentonite

Bentonite deposit Braňany II - Černý vrch, Braňany, Most District, Ústí nad Labem Region, Czech Republic
05141670017271929321235.jpg
Bentonite

Las Cañadas Del Teide, La Orotava, Tenerife, Santa Cruz de Tenerife Province, Canary Islands, Spain
04800110017271929013084.jpg
Cimolite

Kimolos Island, Kimolos, Milos, South Aegean, Greece
01214510017271929318187.jpg
Bentonite

Bentonite deposit Braňany II - Černý vrch, Braňany, Most District, Ústí nad Labem Region, Czech Republic
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About BentoniteHide

An impure clay, primarily montmorillonite, commonly mined for various industrial uses.

Commonly formed by the weathering and alteration of acidic tuffs and related rocks.

Originally described from Fort Benton shales, Wyoming, USA.


Unique IdentifiersHide

Mindat ID:
9141
Long-form identifier:
mindat:1:1:9141:7

Similar NamesHide

BenstoniteA valid IMA mineral speciesBa6Ca6Mg(CO3)13
BentoriteA valid IMA mineral speciesCa6Cr2(SO4)3(OH)12 · 26H2O
K-bentoniteA synonym of 'Potassium bentonite'

Classification of BentoniteHide

Sub-divisions of BentoniteHide

Synonyms of BentoniteHide

Other Language Names for BentoniteHide

Dutch:Bentoniet
Estonian:Bentoniit
Farsi/Persian:بنتونیت
French:Bentonite
Hungarian:Bentonit
Indonesian:Bentonite
Italian:Bentonite
Polish:Bentonit
Portuguese:Bentonita
Romanian:Bentonit
Simplified Chinese:润土
膨润土
Swedish:Bentonit
Turkish:Bentonit

Varieties of BentoniteHide

CimoliteA clay first described from Cimolo, Greece, mentioned by Theophrastos and Pliny.
Present locality name is Kimolos Island (Argentiera), Cyclade Islands (Cyclades; Kikladhes; Nomos Kikladhon), Kykládes Prefecture, Aegean Islands (Aiyaíon) Department, Gree...

Common AssociatesHide

Associations Based on Photo Data:
2 photos of Bentonite associated with CalciteCaCO3
2 photos of Bentonite associated with AragoniteCaCO3
2 photos of Bentonite associated with 'Precious Opal'SiO2 · nH2O

Internet Links for BentoniteHide

References for BentoniteHide

Reference List:
Grim, R.E. and N. Güven (1978), Bentonites. Geology, mineralogy, properties and uses: 143-155. Elsevier, Amsterdam.
Christidis, George E. (1995) Origin of the Bentonite Deposits of Eastern Milos, Aegean, Greece: Geological, Mineralogical and Geochemical Evidence. Clays and Clay Minerals, 43 (1) 63-77 doi:10.1346/ccmn.1995.0430108
Christidis, George E. (1998) Comparative Study of the Mobility of Major and Trace Elements During Alteration of an Andesite and a Rhyolite to Bentonite, in the Islands of Milos and Kimolos, Aegean, Greece. Clays and Clay Minerals, 46 (4) 379-399 doi:10.1346/ccmn.1998.0460403
Christidis, George E. (2001) Formation and Growth of Smectites in Bentonites: A Case Study from Kimolos Island, Aegean, Greece. Clays and Clay Minerals, 49 (3) 204-215 doi:10.1346/ccmn.2001.0490303
García-Romero, Emilia, María Manchado, Eva, Suárez, Mercedes, García-Rivas, Javier (2019) Spanish Bentonites: A Review and New Data on Their Geology, Mineralogy, and Crystal Chemistry. Minerals, 9 (11) 696 doi:10.3390/min9110696
Lorenzo, Adrián, Sánchez-Santos, José Manuel, Rivas, María Jesús, García-Romero, Emilia, Suárez, Mercedes (2024) Geochemistry of bentonites: A statistical analysis of trace element distribution in smectites. Applied Clay Science, 257. 107449 doi:10.1016/j.clay.2024.107449
Li, Lingling; Sun, Haiquan; Fang, Xiaoyu; Lu, Liangliang (2025) The Influence of Temperature on the Microstructure, Atterberg Limits, and Swelling Pressure of Bentonite Clay: A Review. Geosciences, 15 (6). doi:10.3390/geosciences15060233
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