Pattern Formation in a Drying Drop of Starch Gel with Sodium Chloride
  A drop of aqueous potato starch gel with a certain mole fraction of NaCl, when dried on a glass slide, exhibits strong segregation and intricate pattern formation phenomena. The salt forms radial dendritic crystalline aggregates near the centre, with the starch separating out in the form of a transparent band at the periphery. Photographs and micrographs show a series of concentric rings with different texture. 
Moutushi Dutta Choudhury, Sayanee Jana, Sruti Dutta and Sujata   Tarafdar
cond-mat.soft