  Oscillatory zoning, i.e. self-formation of spatial quasi-periodic
oscillations in the composition of solid growing from aqueous solution, is
analyzed theoretically. Keeping in mind systems like (Ba,Sr)SO4 we propose a 1D
model that takes into account the nonideality of the solid solution and the
system asymmetry, in particular, reflecting itself in different solubilities
for such systems. Based on a linear stability analysis different parameter
regions can be identified. Even an ideal solution solution with a sufficiently
large asymmetry can display oscillatory zoning. Numerical simulations
complement the linear stability analysis as well as the qualitative
consideration of the instability development and reveal the nature of the limit
cycles.
