baotite

{{Infobox mineral | name = Baotite | category = Cyclosilicate | image = Baotite-661893.jpg | imagesize = 260px | alt = | caption = Baotite from Sheep Creek, Mineral Point District, Ravalli County, Montana | formula = Ba4Ti4(Ti,Nb,Fe)4(Si4O12)O16Cl |IMAsymbol=Bao | molweight = | strunz = 9.CE.15 | system = Tetragonal | class = Dipyramidal (4/m) H-M symbol: (4/m) | symmetry = I41/a | color = light brown to black | habit = anhedral to subhedral, prismatic and striated parallel to (001) | twinning = | cleavage = fair on {110} | fracture = hackly | tenacity = brittle | mohs = 6 | luster = vitreous | refractive = nω = 1.94,nε > 2.00 | opticalprop = Uniaxial (+) | birefringence = | dispersion = | pleochroism = strong | fluorescence= | absorption = E > O | streak = | gravity = | density = 4.42-4.71 g/mL (measured),4.69 g/mL (calculated) | fusibility = | diagnostic = | solubility = | diaphaneity = | other = | references = }}

Baotite is a rare mineral with the chemical formula Ba4Ti4(Ti, Nb, Fe)4(Si4O12)O16Cl, recognized as having a unique four-fold silicate ring. Crystals are tetragonal, though commonly deformed to the extent of appearing monoclinic. Named for the locality of first discovery, Baotou, China, baotite has been found in hydrothermal veins and alkalic rocks in various locations around the world.