Rhythmic and Zonal Precipitations

Abstract

Rhythmic precipitation of a mineral may occur, not only by inward diffusion of solution into a reacting substance, but also by outward growth of precipitating material, due to intermittent coagulation of a substance in a colloidal medium. Zonal precipitation of different minerals may occur both by successive infiltration of different substances or by their simultaneous diffusion from a mixed solution into a reacting medium. In both cases, the order of succession of resultant zones is fixed according to the reacting materials, not by order of infiltration.