New single-crystal X-ray diffraction and Raman spectroscopic data of natural bismoclite BiOCl

The structure of bismoclite BiOCl from the Jean Baptiste mine, Lavrion area, Greece, was characterised by single-crystal X-ray diffraction. The mineral is tetragonal, space group P4/nmm with unit-cell parameters a = 3.887 (2), c = 7.357 (5) Å, Z = 2, V = 111.16 (14) Å₃ (R₁ = 0.0134 and wR₂ = 0.0363). Bismoclite is isostructural with the mineral matlockite PbFCl. Chemical analyses showed in some cases partial substitution of Bi by Ca and traces of Fe incorporated. A Raman spectrum of bismoclite reveals the most intense Raman band at 144 cm^–1 and additional bands of lower intensity at 198 and 396 cm^–1.