Undulose extinction
= Undulose extinction
{wiki=Undulose_extinction}
Undulose extinction is a phenomenon observed in polarized light microscopy, particularly in the study of mineralogy and petrology. It refers to a form of extinction seen when a birefringent mineral specimen is viewed under cross-polarized light. When a mineral is rotated between crossed polarizers, undulose extinction manifests as a wavy or undulating pattern of extinction, rather than the more typical straight extinction.