Tetravalent lead in nature – plattnerite crystals from Mine du Pradet (France) and Mount Trevasco (Italy)

Natural lead dioxide samples (beta modification) from Cap Garonne, Mine du Pradet, France and Mount Trevasco, Italy were studied by single crystal X-ray and electron diffraction, clearly manifesting the rutile-type structure. A needle from the Mount Trevasco sample was investigated on a single crystal diffractometer: P4(2)/mnm, a = 495.81(10), c = 338.66(7) pm, wR = 0.0513, 117 F-2 values (all data) and nine variables (293 K data). An additional data set at T = 90 K gave no hint for structural distortions.