Falsterite is a rare phosphate mineral[3] with the formula Ca2MgMn2+2(Fe2+0.5Fe3+0.5)4Zn4(PO4)8(OH)4(H2O)14.[2] It is a pegmatitic mineral, related to the currently approved mineral ferraioloite.[3]

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.[2]

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.[2]

References

  1. ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
  2. ^ a b c d 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
  3. ^ a b c "Falsterite: Falsterite mineral information and data". Mindat.org. Retrieved 2016-03-04.
Allikas: https://en.wikipedia.org/wiki/Falsterite
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