A Geoscience Digital Image Library

DescriptionMontmorillonite is a silicate generally located in the clay group. It typically forms microscopic or at least very small platy micaceous crystals. When water is absorbed by the crystals they tend to swell to several times their original volume. This makes montmorillonite a useful mineral for several purposes. It is the main constituent in a volcanic ash called bentonite, which is used in drilling muds. It can also be used by farmers with extended dry periods, engineers of earthen dams or levees or perhaps to plug up old drill holes to prevent leakage of toxic fluids from bottom levels to higher aquifers used for drinking water. Montmorillonites chemical formula is (Na,Ca)0,3(Al,Mg)2Si4O10(OH)2┬Ěn(H2O). It is named after its locality in Veinne, Montmorillone, France.
LocationUSA ▹ Wyoming. Big Horn Mountains.
PhotographerShannon Heinle. 2002-02-10.
CollectionUniversity of North Dakota Mineralogy Collection #1484.
Key wordsmontmorillonite, clay, silicate
Tech details177 KB. Hand specimen. Fujifilm FinePix S1Pro digital camera; 60mm AF Nikon micro lens.
GeoDIL number2341