Bottinoite, Ni(H (sub 2) O) (sub 6) [Sb(OH) (sub 6) ] (sub 2) , a new mineral from the Bottino Mine, Alpi Apuane, Italy

Bottinoite, a new nickel and antimony hydrated hydroxide mineral, occurs at the Bottino mine, Alpi Apuane, Italy. Associated minerals include ullmannite, siderite, calcite, quartz, phlogopite, pyrite, chalcopyrite and an unidentified species containing Sb, Ni and As. The mineral occurs as tabular or very short prismatic crystals with prominent 0001 forming roselike aggregates; crystals <= 0.4 mm and aggregates <= 2.5 mm in diameter. The mineral is light blue-green, transparent, non- fluorescent, with a vitreous lustre and a very light blue streak. It is brittle, with conchoidal fracture; VHN (sub 10) 105 kg/mm (super 2) ; D (sub calc) 2.81 g/cm (super 3) , D (sub meas) 2.83(1) determined for synthetic crystals by heavy liquids. Bottinoite is uniaxial (+), non-pleochroic, with omega.600(1), epsilon 1.605(10), and very low birefringence. It is trigonal, a 16.026(3), c 9.795(2) Angstrom, c/a 0.6112, Z = 6, space group choices are P3 (super -) 1m or, more likely, P31m or P312. The strongest six lines in the XRD powder pattern are 4.62(100), 3.36(100), 2.34(80), 1.806(70), 2.09(60), 1.751(60) Angstrom. On the basis of chemical analysis, IR spectroscopy, TGA, and X-ray data, bottinoite corresponds with the synthetic compound Ni(H (sub 2) O) (sub 6) [Sb(OH) (sub 6) ] (sub 2) . The mineral is named for the Bottino mine, which is the type locality.