C. L. Christ Joan R. Clark 1956 <p>The optical properties of rutherfordine, UO₂CO₃, previously determined on microscopic crystals, have been redetermined on considerably larger crystals; and the relations among the indices of refraction, the morphology, and the crystal structure have been examined. Rutherfordine is orthorhombic, biaxial positive, with α = 1.715, β = 1.730, γ = 1.795, 2V = 53° (calc.); X = b, Y = c (elongation, Z = a. The crystal structure of UO₂CO ₃ consists of layers of carbonate groups parallel to (010) with linear (O-U-O)<sup+2</sup> ions normal to the layers. The indices β and γ correspond to vibration directions parallel to layers; the unexpectedly large difference in value between β and γ is ascribed to the optical anisotropy of the uranium-oxygen bonding in the layer. Indexed X-ray powder data are given.</p> application/pdf 10.3133/tei584 en U.S. Geological Survey Some observations on rutherfordine reports