Cryolite and Ikaite talks – and tribute to Naja Mikkelsen

Since September last year, I have been asked on four different occasions to give a popular science talk on the Greenland minerals, cryolite and ikaite. Both of these minerals originate from the same area in Southwest Greenland. Cryolite was mined in the town of Ivittuut by Arsuk Fjord (see photo above by Elin Tollefsen), whereas ikaite is found in the shape of underwater columns in the neighbouring Ikka Fjord (see map below). What these minerals also have in common besides being white and soft minerals resembling snow, is a common geological ancestral background in the Gardar rocks. The Gardar province encompasses intrusions and meta-sedimentary rocks with unusual mineralogy that formed when a gigantic rift similar to Rift Valley in Africa formed across southern Greenland. Luckily for Greenland this rift arm died out so that Greenland is still in one piece but the rare and precious minerals remain, among these minerals containing the much wanted rare earth elements (REE). Anyway, it has been a real please to give these talks to a highly motivated and engaged audience. Three times in Denmark for Kulturstedet Lindegaarden, Bagsværd Grundejerforening, and Grønlandsmedicinsk Selskab, and once in Sweden for Svenska Mineralogiska Sällskapet (SMS). It was my former colleague from the Danish Polar Center, Henning Thing, who used to give these popular Greenland talks. As Henning sadly passed away two years’ ago, people have now turned to me for similar talks and I’m deeply honoured and humble on taking on this task, because I know Henning was a brilliant presenter. On this note, I would like to express my sincere condolences to the family, friends and colleagues of Naja Mikkelsen, a marine geologist and polar researcher from GEUS. It was almost a shock to learn that Naja very suddenly died of cancer in March this year. My talk at Kulturstedet Lindegaarden was in a series of polar talks together with Naja. However, I have known her my whole geological career. Naja has been well known in Denmark and Greenland in her own right as a geologist with an impressive career but also as the grandchild of famous polar researcher Ejnar Mikkelsen. I have always seen Naja as dedicated and lively person, who like Henning loved to get the fascinating polar stories out to academic and non-academic people alike. An obituary for Naja Mikkelsen can be found at the Geological Society of Denmark’s homepage: https://2dgf.dk/publikationer/geologisk-tidsskrift/geologisk-tidsskrift-2025/