Falsterite is a rare

phosphate In chemistry, a phosphate is an anion, salt, functional group or ester derived from a phosphoric acid. It most commonly means orthophosphate, a derivative of orthophosphoric acid . The phosphate or orthophosphate ion is derived from phospho ...

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 A pegmatite is an igneous rock showing a very coarse texture, with large interlocking crystals usually greater in size than and sometimes greater than . Most pegmatites are composed of quartz, feldspar, and mica, having a similar silicic com ...

, 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 Triphylite is a lithium iron(II) phosphate mineral with the chemical formula LiFePO4.IMA-CNMNC List of Miner ...

and

sphalerite Sphalerite (sometimes spelled sphaelerite) is a sulfide mineral with the chemical formula . It is the most important ore of zinc. Sphalerite is found in a variety of deposit types, but it is primarily in Sedimentary exhalative deposits, sedimen ...

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 , 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

Zinc minerals Calcium minerals Magnesium minerals Manganese(II) minerals Iron(II,III) minerals Phosphate minerals Monoclinic minerals Minerals in space group 14 Minerals described in 2012 {{phosphate-mineral-stub