Induction period, this occurs after adding the precipitating reagent. It is short i.e. Instantaneous to several minutes

Nucleation this is where a minimum # of ions, atoms or molecules join together to give a stable solid. It is from this that crystals grow. After Nucleation large nuclei grow at the expense of smaller nuclei which dissolves.This process helps produce more easily filtered crystals since large crystals are produced

Growth of larger nuclei or crystals can be encouraged by digestion which involves heating the solid and mother liquor for a certain amount of time. During digestion small particles dissolve and larger ones grow.

Mechanism of Precipitation