Allophane

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.