serandite

{{infobox mineral | name = Serandite | category = Inosilicates | boxwidth = | boxbgcolor =#FA8072 | image = Serandite-Aegirine-20264.jpg | imagesize = 260px | caption = Serandite from Mont Saint-Hilaire, Quebec, Canada | formula = Na(Mn2+,Ca)2Si3O8(OH) | IMAsymbol = Srd | molweight = | strunz = 9.DG.05 | dana = 65.2.1.5 | system = Triclinic | class = Pinacoidal () (same H-M symbol) | symmetry = P | unit cell = a = 7.683(1) Å, b = 6.889(1) Å c = 6.747(1) Å, α = 90.53(5)° β = 94.12(2)°, γ = 102.75(2)° Z = 2 | color = | habit = | twinning = Around [010] composition plane {100}, less commonly contact twin on {110} | cleavage = Perfect on {001} and {100} | fracture = Irregular, uneven | tenacity = Brittle | mohs = 5 to 5.5 | luster = Vitreous to greasy; fibrous aggregates are dull to silky | polish = | refractive = nα = 1.668nβ = 1.671nγ = 1.703 | opticalprop = Biaxial (+) | birefringence = δ = 0.035 | 2V = 39° | dispersion = r 3 (measured) | melt = | fusibility = | diagnostic = | solubility = | diaphaneity = Transparent, Translucent | other = | references = |colour=salmon pink to orange}} Serandite is a mineral with formula Na(Mn2+,Ca)2Si3O8(OH). The mineral was discovered in Guinea in 1931 and named for J. M. Sérand. Serandite is generally red, brown, black or colorless. The correct name lacks an accent.

==Description== Serandite is transparent to translucent and is normally salmon-pink, light pink, rose-red, orange, brown, black, or colorless; in thin section, it is colorless. Octahedrally bonded Mn(II) is the primary contributor to the mineral's pink colors.