clay material domdom
F. Clay Materials
F.1 Kaolinite
Kaolinite from chinese word “Gaoling”is a clay mineral,part of industrial minerals
with a soft consistency and earthy texture.The chemical composition
Al2Si2O5(OH)4. Rocks that are rich in kaolinite are known as kaolin or china
clay.It is easily broken and can be molded or shaped, especially when wet.
Kaolinite is a lackluster and uninteresting mineral on its own, but it occasionally
forms interesting pseudomorphs, especially after feldspars. It is also a common
accessory to other minerals, including gem crystals in decomposing
feldsparpegmatites.
F.2 Illite
Illite (the name was derived from its type location in Illinois) is a group of closely
related non-expanding clay minerals. Illite is a secondary mineral precipitate, and
an example of a phyllosilicate, or layered alumino-silicate. Illite occurs as an
altered product of muscovite
and feldspar in weathering and hydrothermal environments; it may be a
component of sericite.Illite is also called hydromica or hydromuscovite.
F.3 Montmorillonite
Montmorillonite is a very soft phyllosilicate group of minerals that form when they
precipitate from water solution as microscopic crystals, known as clay. Named
after Montmorillon in France. The individual crystals of montmorillonite clay are
not tightly bound hence water can intervene, causing the clay to swell. Its
water content is variable and it increases greatly in volume when it absorbs water.
Often intermixed with chlorite, muscovite, illite, cookeite, and kaolinite. Used in
the oil drilling industry as a component of drilling mud, making the mud
slurry viscoushelps in keeping the drill bit cool and removing drilled solids. It is used
as a soil additive to hold soil water in drought-prone soils, used in the construction
of earthen dams and levees to prevent the leakage. And also as a component
of foundry sand and as a desiccant to remove moisture from air and gases.
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