Dorfmanite
Dorfmanite is an IMA-recognized mineral species in the phosphate class, with the chemical formula Na₂(PO₃OH)·2H₂O.
It crystallizes in the orthorhombic crystal system (space group Pbca).
Key properties: Mohs hardness 1–1.5; specific gravity 1.98–2; Vitreous to earthy luster; optically biaxial.
IMA symbol Dfm, IMA status: approved, named in 1979.
Noted in drill cores into alkalic pegmatites in differentiated alkalic massifs, as an alteration product of lomonosovite and nacaphite (Kola Peninsula, Russia).
It is found associated with Lomonosovite, olympite, villiaumite (Kola Peninsula, Russia); sodalite, villiaumite, eudialyte, lovozerite, ussingite (Mont Saint-Hilaire, Canada).
The mineral was named to honor Moisei Davidovich Dorfman (1908–), Russian mineralogist, A.E. Fersman Mineralogical Museum, Moscow, Russia, investigator of Khibiny minerals.