mckelveyite-(Y)

{{Infobox mineral | name = Mckelveyite-(Y) | category = Carbonate mineral | boxwidth = | boxbgcolor = | image = Mckelveyite-(Y).jpg | imagesize = | caption = Mckelveyite-(Y) found in Canada | formula = Ba3Na(Ca,U)Y(CO3)6·3H2O | IMAsymbol = Mkv-Y | molweight = | strunz = 5.CC.05 | system = Triclinic | class = Pedial (1) (same H-M symbol) | symmetry = P1 | unit cell = a = 9.170(3) Å, b = 9.169(3) Å, c = 7.075(2) Å; α = 102.50(3)°, β = 115.63(3)°, γ = 59.99(3)°; Z = 1 | color = Lime-yellow, greenish gray, reddish brown, may be black from contained organic material | habit = Tabular, pyramidal | twinning = Threefold (pseudorhombohedral about {0001}) | cleavage = Indistinct | fracture = | tenacity = | mohs = 3.5–4 | luster = Vitreous, greasy, or dull | polish = | refractive = nα = 1.550–1.554 nβ = 1.550–1.554 nγ = 1.649–1.658 | opticalprop = Biaxial (−) | birefringence = δ 0.0990–0.1040 | dispersion = | pleochroism = Visible | fluorescence= | absorption = | streak = White | gravity = 3.25 | density = | melt = | fusibility = | diagnostic = | solubility = | diaphaneity = Transparent to opaque | other = 25px Radioactive | references = }}

Mckelveyite-(Y) is a hydrated sodium, barium, yttrium, and uranium–containing carbonate mineral, with the chemical formula Ba3Na(Ca,U)Y(CO3)6·3H2O.