///The babingtonite occurred in the drusy cavities of Permian period Emeishan basalt, Yunnan province. Its crystal habit is tabular and prismatic, parallel with crystal face(100).The resulting chemical formula of the Emeishan babingtonite sample is Ca2.037(Fe2+0.709Mn2+0.187Mg2+0.063)0.959Fe3+1.182[(Si4.997Al0.003)5.0O14.768(OH)0.232].The crystal structure of the babingtonite is determined from X-ray powder diffraction data by Rietveld method. The space group is confirmed to be P1-with unit cell parameters: a=0.746 6(1)nm, b=1.163 1(2)nm, c=0.668 4(1) nm, α=91.554(4)°, β=93.889(3)° and γ=104.193(3)°.The Rietveld refinement of the data is converged to Rp=0.035 1, Rwp=0.045 4, Rexp=0.028 86 and χ2=2.475.In the unit cell of babingtonite crystal, two silica-oxygen tetrahedron single chains extend along , and connected with distorted iron-oxygen octahedron and distorted calcium-oxygen dodecahedron.
