Aphthitalite, (K, Na)₃ Na(SO₄)₂ occurs as a daughter mineral in magmatically derived fluid inclusions in quartz from the Eikeren-Skrim granite complex in the Oslo paleorift. Laser Raman microspectrometry (LRM) was performed on daughter grains and reference samples of aphthitalite. The identity of the mineral was also checked using energy dispersive X-ray spectra (EDS) from opened fluid inclusions.

Thor H. Hansteen, Mineralogicai-Geological Museum, Sars Gate 1, N-0562 Oslo 5. Present address: GEOMAR, Wischhofstrasse 1-3, D-24148 Kiel, FRG;
Ernst A. J. Burke, The Free University, Faculty of Earth Sciences, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands.