Reflections: Chemical cocktail

A chemical cocktail, smeared on a glass slide, self assembles into a large number of convective cells. Within each cell there is a point called a nucleation site from which crystallization occurs via self assembly. This is a close up of one of the cells. The crystalline film itself is colorless and translucent to the unaided eye; however, when viewed through polarized light and using a retarder, an exquisite formation that resembles a flower is revealed. The cocktail consists primarily of ammonium iron sulphate. This photo is the winner of the Technology Category, 2022 International Day of Light Photo Contest. Photo credit: PFG Precision Optic