Urea Crystals
A yellow stain near the molding on a bathroom floor wassuspected to be fungal growth. This is from an environmental tapelift of the stain. The large crystals seen here are urea.
Transmitted Crossed Circular Polarized Light
Definition/Function:
Urea is CO(NH2)2. It is excreted by mammals in the urine as a breakdown product of protein.
Significance in the Environment:
Urea is a common marker for urine stains in indoor environments. Pet related stains on floors or rodent paths are common locations associated with urea from mammalian urine.
Characteristic Features:
Urea is a colorless, optically positive, tetragonal crystal with refractive indices of 1.484 (omega) and 1.602 (epsilon).
Associated Particles:
When part of a deposit from urine it is associated with sodium chloride and other organic and inorganic salts.
