Abstract
The nature of amorphous silicates, allophane, ö The name allophane is used in this paper in a dual sense; the one stands for a group of amorphous or nearly amorphous aluminum silicates associated with minor amounts of other metals, and the other in some restricted sense for amorphous silicates other than imogolite. The latter term, imogolite, is used for convenience to denote a component that shows broad x-ray diffractions at 14 (strong), 7.6 (medium) and 5.6 (weak) Å, gives an endotherm at 430°C, and appears as thread-like particles of diameter 100 to 200 Å in electronmicrographs (21). View all notes as a main clay constituent determines many of the physical and chemical properties of volcanic ash soils. Recent developments in the study of allophane together with other amorphous inorganic materials in relation to their nature and occurrence in soils have been reviewed by MITCHELL et al. (12).