Suvarna Garge (Editor)

Falsterite

Updated on
Edit
Like
Comment
Share on FacebookTweet on TwitterShare on LinkedInShare on Reddit
Category
  
Phosphate mineral

Space group
  
P21/c

Crystal system
  
Monoclinic

Formula(repeating unit)
  
Ca2MgMn2(Fe0.5Fe0.5)4Zn4(PO4)8(OH)4(H2O)14

Crystal class
  
Prismatic (2/m)(same H-M symbol)

Unit cell
  
a = 6.39, b = 21.26c = 15.37 [Å]; β = 90.56° (approximated); Z = 2

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

Contents

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.

    References

    Falsterite Wikipedia
    (Text) CC BY-SA


    Similar Topics