Microscopic Pigments

One technique used by conservation scientists to identify pigments is polarized light microscopy. Using a microscope, one can determine certain characteristics about an unknown pigment, such as optical properties, particle size, and shape.

The two green pigments below can be differentiated by their shape and color. Compare the starburst shape of the emerald green pigments to the coarse, fractured particles of viridian.

Emerald green, 1000x
(Photo credit: McCrone Research Institute)
Viridian, 400x
(Photo credit: McCrone Research Institute)