A general term, now obsolete, to describe any poorly defined, fine grained manganese oxide with black or dark brown earthy, dull luster.
Cf., psilomelane.
A general term, now obsolete, to describe any poorly defined, fine grained manganese oxide with black or dark brown earthy, dull luster.
Cf., psilomelane.
A poorly defined material, possibly a mica.
An obsolete varietal term for clintonite.
An obsolete varietal term for clintonite.
An obsolete varietal term for clintonite.
The degree of soil water content is defined by the fraction, by mass or weight, of pore water relative to the total dry soil solid particles, usually expressed as a percentage. In practice, soil water content is measured by heating a wet soil sample at 105 – 110oC to a constant mass. The weight loss by heating is assumed to be the weight of water, and the residual weight is the weight of dry soil solids.
Syn., moisture content
Cf., water saturation, degree of;
H2O molecules attracted to internal or external surfaces of a phyllosilicate, or other material, and adhered to these surfaces in thicknesses of one or more molecules. The term “water” (rather than “H2O”) is not precisely used here because “water” is a (liquid) phase. Elevated temperatures, typically 110oC for 12 hours, can desorb the adhered H2O. However, for phyllosilicates, a temperature of 110oC may not liberate all the adsorbed water molecules present, and temperatures of as high as 300oC (in special cases, even higher) may be needed for some vermiculites and smectites.
Syn. absorbed water
Cf., water, structural
The degree of water saturation is the ratio of pore water volume to the total void volume, usually expressed as a percentage. In soil science, values may range from 0 % for a dry soil to 100% for a soil with its void fully occupied by water. Water saturation of a soil refers to the latter.
See also water content
H2O adsorbed by soil that is equilibrated with the atmosphere to which it is exposed at a given temperature and relative humidity, usually 25oC at 98 % relative humidity.
Water (or more precisely, H2O molecules) adsorbed between the (1:1 or 2:1) layers of a phyllosilicate. The use of “water” is a misnomer because the interlayer H2O is not equivalent to bulk water (i.e., a phase, a liquid), which involves randomly oriented H2O. Instead, the interlayer H2O is affected structurally by the adjacent 1:1 or 2:1 layers and by the cations present in the interlayer.
Cf., water, adsorbed