The central concept of
Spodosols is that of soils in which amorphous mixtures of organic
matter and aluminum, with or without iron, have accumulated. In
undisturbed soils there is normally an overlying eluvial horizon,
generally gray to light gray in color, that has the color of more or
less uncoated quartz.
Most Spodosols have little silicate clay. The particle-size class
is mostly sandy, sandy-skeletal, coarse-loamy, loamy, loamy-
skeletal, or coarse-silty.