Formula: Mn2+Fe3+2(PO4)2(OH)2.4H2O
Hydrated phosphate containing hydroxyl, arthurite group, manganese-bearing mineral
Specific gravity: 2.90 measured, 2.92 calculated
Hardness: 3 to 4
Streak: Light brown
Colour: Dark reddish brown, yellowish brown, yellow-orange, bright yellow
Luminescence: No fluorescence under UV



From the Hagendorf South Pegmatite, Hagendorf, Waidhaus, Neustadt an der Waldnaab District, Upper Palatinate, Bavaria, Germany, earlshannonite was discovered on a specimen labeled as rockbridgeite. On this specimen, bright yellow, divergent sprays of earlshannonite form an encrustation on rockbridgeite-frondelite (CM 22.471-474).

The Emmons pegmatite, Greenwood, Oxford county, Maine, USA, is situated in a belt of metasedimentary rocks which originated as marine sediments which were subsequently deformed and metamorphosed. The Emmons pegmatite is an example of a highly evolved boron-lithium-cesium-tantalum enriched pegmatite. Earlshannonite occurs here, usually associated with hureaulite, strunzite, phosphoferrite and mitridatite (R&M 94.6.506).

At the type locality, the Foote Lithium Co. Mine, Kings Mountain Mining District, Cleveland county, North Carolina, USA, earlshannonite was found on the mine dumps as radial aggregates of crystals to 0.5 mm in a pegmatite. On the type specimens, the quartz matrix has a thin, dull green coating of mitridatite, which is in turn coated by randomly distributed crystals and crystal clusters of laueite, a jahnsite-group mineral, rockbridgeite and earlshannonite. Sequential growth relationships are ambiguous, but earlshannonite is among the last species to form in the sequence of late-stage secondary phosphates. The phosphate species are coated by bulbous, irregular aggregates of a manganese oxide (CM 22.471-474).

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