Specific mass increment and nonequilibrium crystal growth

Unsteady nonequilibrium crystallization of ammonium chloride from an aqueous solution resulting in the formation of irregular, so-called seaweed, structures is experimentally investigated. It is shown that specific increment of mass for the coexisting structures (or parts thereof) is the same and changes with time (t)$\left(t\right)$ according to the power law a/t−b$a/t-b$, where the factor a=1.87±0.09$a=1.87\pm 0.09$ and the factor b$b$ is determined by the system relaxation time. The normalization of the power law to the total time of structure growth allows obtaining a universal law that describes the specific mass increment with time for both seaweed and dendrite structures (including the non-coexisting ones).