Oxalic acid is present in the sap of many plants and is common in vegetables as the potassium or calcium salt. Commercially, oxalic acid is manufactured by passing carbon monoxide into concentrated sodium hydroxide. Oxalic acid has a number of uses including calico printing and dyeing, paint removal, metal polishes, in ceramics, and as a cleaner in metallurgy. When recrystallized from the melt, oxalic acid will slowly crystallize, forming beautiful dendritic needle-like crystals that comprise spherulite structures. The time-lapse movie was made using a modified version of the Intel Play QX3 microscope equipped for polarized light illumination with a full-wave (first order) retardation plate.