cymrite

{{Infobox mineral | name = Cymrite | category = Phyllosilicate minerals | boxwidth = | boxbgcolor = | image = Cymrite-352204.jpg | imagesize = | caption = Cymrite (2.2 x 1.6 x 1.6 cm) | formula = BaAl2Si2(O,OH)8·(H2O) | IMAsymbol = Cym | system = Monoclinic | class = Domatic (m) (same H-M symbol) | symmetry = Pm | unit cell = a = 5.32 Å, b = 36.6 Å, c = 7.66 Å; β = 90°; Z = 2 | color = Brown, greenish, colorless | habit = Micacious, sheet-like, pseudohexagonal, also fibrous | twinning = | cleavage = Perfect on {001}, good on {110} | fracture = Uneven | tenacity = Brittle | mohs = 2-3 | luster = Silky, Vitreous | refractive = nα = 1.611 nβ = 1.619 nγ = 1.621 | opticalprop = Biaxial (-) | 2V = 0-5° | birefringence = δ = 0.010 | pleochroism = | streak = White | gravity = 3.49 | density = | melt = | fusibility = | diagnostic = | solubility = | diaphaneity = Transparent to translucent | other = | references = }}

Cymrite is a silicate mineral with the chemical formula BaAl2Si2(O,OH)8·H2O. The mineral is named for Cymru, which is the Welsh word for Wales.