Polar stratospheric cloud or mother of pearl or nacreous clouds as they called this phenomenon. This one is from Lofoten islands Stock-Foto | Adobe Stock
UK weather: These rainbow Nacreous clouds are beautifully haunting | Metro News
Rare 'mother-of-pearl' cloud spotted in Scotland - BBC News
World Meteorological Organization - Beautiful and oh so rare Ice Polar Stratospheric clouds (nacreous clouds) spotted near Oslo, Norway by Snezana Dakovic. Also known as mother-of-pearl clouds, they occur mainly at high