Montmorillonite is a clay mineral of the smectite group, which also includes nontronite and saponite. It was first discovered in 1847 in Montmorillon in the Vienne region of France. It is usually white, gray, or pink with shades of green or yellow as a result of the metal oxide impurities it contains. It is often found in compact or lamellar masses, but never in large individual crystals. Its specific gravity varies between 1.7 and 3.0. It has a hardness of 1–2 in the Mohs scale (the Mohs scale ranges between 1 and 10, where 1 and 10 correspond to talc and diamond, respectively). Chemically, it is a hydrated aluminum silicate containing small amounts of magnesium, iron, sodium, calcium, and potassium as a result of isomorphic substitutions. The nature of these cations and their ratio within the mineral structure vary with the source of montmorillonite.
KeywordsCatalyst Cation exchange Clay minerals Oligomerization Origin of life
References and Further Reading
- Grim RE (1968) Clay mineralogy. McGraw Hill, New YorkGoogle Scholar