Anhydrous phosphate containing hydroxyl, triplite group, forms a series with triploidite
Specific gravity: 3.79 to 3.82
Hardness: 4½ to 5
Streak: White, off-white
Colour: Red-brown to dark brown, green (rare); light brown in transmitted light.
Solubility: Soluble in acids
Wolfeite is a secondary mineral formed by hydrothermal alteration of
triphylite in complex zoned granite pegmatites,
rarely in hydrothermal veins and in phosphatic nodules in shale. Associated minerals include
hagendorfite, arrojadite and
apatite in pegmatites, and wicksite,
satterlyite and maricite in
At Skrumpetorp, Godegård, Motala, Östergötland County, Sweden, wolfeite occurs with triplite (Dana).
The type locality is the Palermo Number 1 Mine, Groton, Grafton county, New Hampshire, USA, which is hosted by a granite pegmatite. Wolfeite was first noticed as a hydrothermal replacement of triphylite, associated with indistinct veinlets containing chlorite, sphalerite, pyrite and arsenopyrite. Further operations in the quarry exposed a large triphylite crystal that had been partly reworked hydrothermally into a granular aggregate composed of residual triphylite, siderite, quartz, apatite, plagioclase, ludlamite and wolfeite (AM 34.692-698).
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