Earlshannonite Locality: Foote Lithium County Mine (Foote Mine), Kings Mountain District, Cleveland County, North Carolina , USA ( Locality at mindat.org ) Redbrown cluster of Earlshannonite on brown Mitridatite balls. Field of view 3 mm. Specimen and photo Leon Hupperichs. — Photo: Leon Hupperichs · CC BY-SA 3.0
Earlshannonite
Earlshannonite is an IMA-recognized mineral species in the phosphate class, with the chemical formula Mn²⁺Fe³⁺₂(PO₄)₂(OH)₂·4H₂O.
It crystallizes in the monoclinic crystal system (space group P2_1/c). It is a member of the Arthurite structural group.
Key properties: Mohs hardness 3–4; specific gravity 2.9; Pale brown streak; Vitreous luster; optically biaxial.
IMA symbol Esn, IMA status: approved, named in 1983.
A very late-stage secondary mineral in a lithium-rich granite pegmatite (Foote mine, North Carolina, USA).
It is found associated with Jahnsite, laueite, mitridatite, rockbridgeite, manganese oxide, quartz (Foote mine, North Carolina, USA); rockbridgeite–frondelite (Hagendorf, Germany).
The mineral was named to honor Earl V. Shannon (1895–1981), American mineralogist and chemist, U.S. National Museum, Washington, D.C., USA.