[Agricultural Uses]
Allophane is a general term for amorphous,
aluminosilicate gels of a wide range of composition,
commonly found in volcanic soils. They have a very high
phosphorus retention capacity. Most clay minerals have a
layer-lattice structure, but a small group of allophanes
form hollow spherical crystals.
Allophane and imogolite are most commonly found in
relatively young soils (< 10,000 years) formed on
volcanic ash and pumice. Allophane exists as a hollow,
nearly spherical particle with a diameter of 3.5 to 5 nm. |