Formula: ZnMn2+Fe2+2Fe3+(PO4)34(OH)24(H24O)74.2H24O
Hydrated phosphate, schoonerite group, zinc- and manganese- bearing mineral
Specific gravity: 2.87 to 2.92 measured, 2.79 calculated
Hardness: 4
Streak: Pale brown
Colour: Pale tan to brown, greenish brown, reddish brown to bronzy on weathered surface
Luminescence: Not fluorescent in UV
Solubility: Rapidly soluble in hydrochloric acid

Hydrothermal environments


At the type locality, the Palermo No. 1 Mine, Groton, Grafton County, New Hampshire, USA, numerous posphate pods are found in the palermo pegmatite. Schoonerite is a very sparse but widely distributed phase, occurring locally in minute quantities. It is the latest product in the assemblage; associated phases include mitridatite, laueite, strunzite, whitmoreite and iron-manganese oxyhydroxides. It has been noted as local patches and mats coating thin fracture surfaces cutting whitlockite-apatite rock, usually upon a thin black base of the oxides. It also occurs as scattered to bunched thin, friable laths in small open cavities in siderite, ludlamite and messelite, and in solution cavities in vivianite, which schoonerite replaces. Schoonerite is thought to be a product of low-temperature hydrothermal attack, weathering and oxidation of more reduced phases such as triphylite, ludlamite, vivianite and sphalerite, all of which occur as common constituents of the pods.
Two samples illustrate different paragenetic settings for schoonerite:
One is a mass of dense fine-grained whitlockite and hydroxylapatite. Granular siderite occurs along one side of the mass. Implanted upon solution cavities in the whitlockite and apatite are radial aggregates of childrenite, warty brown jahnsite, and a film of dull green mitridatite. The schoonerite occurs as copper-red glistening scales and mats across the surface, the latest mineral in the sequence.
The second sample is the type sample itself, which came from a triphylite pod; portions of the triphylite, especially along the periphery, are completely replaced by granular siderite, coarse patches of ludlamite, and remnant arrojadite. Cavities in the sample are studded with lustrous siderite rhombohedra, bipyramids of quartz, colourless cockscomb aggregates of messelite, and pale blue laths of vivianite. Upon these are perched radial sprays of whitmoreite, orange laths of jahnsite, a dull green layer of mitridatite, and thin laths of the schoonerite. The sequence is triphylite →arrojadite →ludlamite →siderite →messelite →vivianite →mitridatite → rockbridgeite →jahnsite →whitmoreite →schoonerite. The schoonerite is brown to copper-red and occurs as isolated laths to bunches of flattened strawlike aggregates up to 2 mm in length.
The limited occurrence of schoonerite may result from the fact that few pegmatites carry significant quantities of the zinc minerals necessary for its production (AM 62.246-249).

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