• journal_title：European Journal of Mineralogy
• Contributor：Thomas Malcherek ; Boriana Mihailova ; Jochen Schlüter ; Tomas Husdal
• Publisher：E. Schweizerbart'sche Verlagsbuchhandlung Science Publishers
• Date：2012-10-01
• Format：text/html
• Language：en
• Identifier：10.1127/0935-1221/2012/0024-2242
• journal_abbrev：Eur J Mineral
• issn：0935-1221
• volume：24
• issue：6
• firstpage：1053
• section：Articles

The title mineral has been discovered in a granitic pegmatite at the Stetind quarry, Tysfjord, Norway. Atelisite-(Y) forms pale brown to colourless, transparent crystals of dipyramidally terminated, short-prismatic habit with a diameter of up to 0.3 mm. Based on electron microprobe analysis and 16 anions per formula unit, the empirical formula is (Y_3.11Yb_0.46Er_0.19Dy_0.11Gd_0.09Ho_0.01Tb_0.02)_∑3.99Si_2.40O₁₆H_10.43 The presence of hydroxyl-groups is inferred from the detection of OH-stretching modes near 3225 cm⁻¹ in Raman spectra of the new mineral. The crystal structure of atelisite was solved and refined on single-crystal X-ray diffraction data in space group I4̄2d, with a = 6.947(4), c = 6.133(3) Å, V = 295.98(28) ų. Site occupancy refinement at the 4a-site approaches 3/4 Si-occupancy, if the 4b-site is fully occupied by Y and Yb, with a refined Y/Yb ratio of 4. This suggests an idealized formula of Y₄Si₃O₈(OH)₈ for atelisite-(Y). The crystal structure of the new mineral is of particular interest with regard to the known occurrence of hydrous species in the nominally anhydrous minerals xenotime and zircon.