Bonacinaite, IMA 2018-056

Bonacinaite Sc(AsO4)·2H2O In the dumps of the Varenche mine, SaintBarthélemy valley, Nus, Val d'Aosta, Italy (45° 47'25"N, 7°28'55"E). The As-analogue of kolbeckite Monoclinic: P21/n; structure determined a=5.533(1), b=10.409(2), c=9.306(2) Å, ?= 91.94(3)° 4.865(100), 4.638(18), 4.525(32), 3.771(34), 2.924(44), 2.759(31), 2.665(94), 1.733(36) Type material is deposited in the mineralogical collections of the Museum of the Earth Sciences Department, University of Milano, catalogue number MCMGPG-H2018-001 (holotype), the Natural History Museum, Vienna, catalogue number O 571 (crystal used for the crystal structure determination), and the Laboratory of Mineralogy, University of Lie?ge, Belgium, catalogue number 21180 (crystal used for optical measurements)