marialite

{{Infobox mineral |boxbgcolor=#d1b05c| name = Marialite | image = Marialite-169082.jpg | imagesize = 260px | alt = | caption = | category = Tectosilicate minerals | group = Scapolite group | formula = | IMAsymbol = Mar | strunz = 9.FB.15 | dana = | system = Tetragonal | class = Dipyramidal (4/m) (same H-M symbol) | symmetry = I4/m | unit cell = a = 12.06 Å, c = 7.572(3) Å; Z = 2 | color = Colorless, white, grey; pink, violet, blue, yellow, brown, orange-brown, pale green or reddish | colour = | habit = Typically flat, pyramidal striated crystals; massive, granular | twinning = | cleavage = Distinct on {100} and {110} | fracture = Uneven to conchoidal | tenacity = Brittle | mohs = –6 | luster = Vitreous, pearly, resinous | streak = White | diaphaneity = Transparent to opaque | gravity = 2.55–2.74 | density = 2.5–2.62 g/cm3 | polish = | opticalprop = Uniaxial (−) | refractive = nω = 1.539–1.550 nε = 1.532–1.541 | birefringence = δ = 0.007 – 0.009 | pleochroism = | 2V = | dispersion = | extinction = | length fast/slow = | fluorescence = | absorption = | melt = | fusibility = | diagnostic = | solubility = | impurities = | alteration = | references = }}

Marialite is a silicate mineral with a chemical formula of if a pure endmember or with increasing meionite content. Marialite is the sodium endmember of the scapolite group and a solid solution exists between marialite and meionite, the calcium endmember. It is a rare mineral usually used as a collector's stone.