falsterite

{{infobox mineral | name = Falsterite | category = Phosphate mineral | image = | imagesize = | alt = | caption = | formula = Ca2MgMn2+2(Fe2+0.5Fe3+0.5)4 Zn4(PO4)8(OH)4(H2O)14 | IMAsymbol = Fls | strunz = | dana = | system = Monoclinic | class = Prismatic (2/m) (same H-M symbol) | symmetry = P21/c | unit cell = a = 6.39, b = 21.26 c = 15.37 [Å]; β = 90.56° (approximated); Z = 2 | color = Greenish-blue | colour = | habit = thin plates, rectangular laths | twinning = | cleavage = {010}, perfect | fracture = Uneven | tenacity = | mohs = | luster = Vitreous | streak = Very pale greenish-blue | diaphaneity = Transparent | gravity = | density = 2.78 (measured); 2.84 (calculated; approximated) | polish = | opticalprop = Biaxal (-) | refractive = nα=1.58, nβ=1.60, nγ=1.61 (approximated) | birefringence = | pleochroism = Colorless to very pale yellow (X & Z), blue-green (Y) | 2V = | dispersion = Strong | extinction = | length fast/slow = | fluorescence = | absorption = | melt = | fusibility = | diagnostic = | solubility = | impurities = | alteration = | other = | references = }} 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.

==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.