Typical association from Palermo mine (Palermo 1 Mine, Grafton County, New Hampshire, United States of America): crystals of goedkenite grown on prismatic crystals of palermoite. Goedkenite is a Sr phosphate known from only two localities worldwide while palermoite is another Sr phosphate that has only been found in the three localities worldwide. This specimen is from the type locality for both species. — Photo: David Hospital · CC BY-SA 4.0
Goedkenite
Goedkenite is an IMA-recognized mineral species in the phosphate class, with the chemical formula Sr₂Al(PO₄)₂(OH).
It crystallizes in the monoclinic crystal system (space group P2_1/m). It is a member of the Brackebuschite structural group.
Key properties: Mohs hardness 5; specific gravity 3.83; Subadamantine luster; optically biaxial.
IMA symbol Goe, IMA status: approved, named in 1974.
A rare late-stage secondary hydrothermal mineral in a complex granite pegmatite.
It is found associated with Palermoite, childrenite, bjarebyite, goyazite, whitlockite, carbonate apatite, siderite, quartz.
The mineral was named to honor Dr. Virgil Linus Goedken (1940–1992), Department of Chemistry, University of Chicago, Chicago, Illinois, USA.