Falsterite is a rare phosphate mineral with the formula Ca2MgMn2+2(Fe2+0.5Fe3+0.5)4Zn4(PO4)8(OH)4(H2O)14.Kampf, A.R., Mills, S.J., Simmons, W.B., Nizamoff, J.W., and Whitmore, R.W., 2012. Falsterite, Ca2MgMn2+2(Fe2+0.5Fe3+0.5)4Zn4(PO4)8(OH)4(H2O)14, a new secondary phosphate mineral from the Palermo No. 1 pegmatite, North Groton, New Hampshire. American Mineralogist 97(4), 496-502 It is a pegmatitic mineral, related to the currently approved mineral ferraioloite.
Occurrence and association Falsterite was found in Palermo No. 1 pegmatite, North Groton, Grafton County, New Hampshire, US. Co-type locality is pegmatite at Estes quarry, Baldwin, Cumberland County, Maine, US. Falsterite is a product of alteration of triphylite and sphalerite.
Crystal structure Main features of the crystal structure of falsterite, which is somewhat similar to that of schoonerite, are: chains of Fen+O6 octahedra, displaying edge-sharing chains of ZnO4 tetrahedra, that display corner-sharing sheets, parallel to {010}, formed by linking the above two types of chains by PO4 tetrahedra slabs formed by linking the sheets with MnO6 octahedra and CaO7 polyhedra The slabs are bridged by dimers of MgO6 octahedra that display edge-sharing. Magnesium-bearing octahedra share edges with zinc-bearing tetrahedra.
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