“Thin section viewed in cross-polarized light of chalcedony filling a vug in chert. The chalcedony is partially stained by iron oxide. The peculiar banding is called wrinkle banding ("Runzelbänderung"--thanks Amir Akhavan!), and is only visible in thin section using cross-polarized light. Collected, processed, and photographed by Norman King.”
Norman King - 4th October 2014