Outstanding dark orange single crystal of the extremely rare mineral bøggildite from the TL and only known locality in Ivigtut (Ivigtut, Ivittuut, Arsuk Fjord, Sermersooq, Greenland). Ex Vandenbroucke Museum collection from Waregem, Belgium. — Photo: David Hospital · CC BY 4.0
Bøggildite
Bøggildite is an IMA-recognized mineral species in the phosphate class, with the chemical formula Na₂Sr₂Al₂(PO₄)F₉.
It crystallizes in the monoclinic crystal system (space group P2_1/c).
Key properties: Mohs hardness 4–5; specific gravity 3.66; Vitreous, greasy on fracture surfaces luster; optically biaxial.
IMA symbol Bgg, grandfathered status — known before the IMA’s founding, named in 1951.
A rare mineral within greisen formed at the contact zone of a cryolite ore body.
It is found associated with Fluorite, cryolite, sphalerite, pyrite, zircon, chalcopyrite, galena, molybdenite, albite, muscovite, quartz.
The mineral was named to honor the Danish mineralogist Ove Balthasar Bøggild (1872–1956), Professor of Geology, University of Copenhagen, Copenhagen, Denmark.