Ozernovskite, Fe 3+ 4 (Te 4+ O 4 )(Te 4+ O 3 ) 4 (H 2 O) 7 , a new supergene mineral with a unique crystal structure containing two types of tellurite polyhedra

The new mineral ozernovskite, ideally Fe 3+ 4 (Te 4+ O 4 )(Te 4+ O 3 ) 4 (H 2 O) 7 , was found in the oxidation zone of the Ozernovskoe gold deposit, Kamchatka, Russia and named after the locality; IMA-accepted symbol is Ozn.The associated minerals are sonoraite, mandarinoitetelluromandarinoite series members, poughite, emmonsite, tellurite and goethite; the primary minerals in this assemblage are Se-enriched native tellurium, pyrite, maletoyvayamite, tetrahedrite-group minerals of the goldfieldite series, fischesserite, gachingite, bohdanowiczite, paraguanajuatite, enargite, quartz, dickite, and baryte.Ozernovskite occurs as long-prismatic to acicular crystals up to 0.03 × 0.05 × 1 mm 3 usually assembled in sprays, radial clusters, bush-like aggregates or spherulites up to 2 mm across which sometimes form incrustations up to 1 × 2.5 cm 2 .It is transparent, olive green, yellowish-green or yellow, with vitreous lustre.D calc. is 3.812 g/cm 3 .Ozernovskite is optically biaxial (-), α 1.915(10), β 1.94(1), γ 1.95(1); pleochroism is weak: Z (pale yellow) > Y (very pale yellow) > X (colourless).The IR spectrum is given.The chemical composition (wt.%, electron microprobe, H 2 O by stoichiometry) is Fe 2 O 3 25.85,SeO 2 2.69, TeO 2 60.12,As 2 O 5 0.57, SO 3 0.08, H 2 O calc 10.14, total 99.58.The empirical formula, calculated based on 23 O apfu, is Fe 3+ 3.98 (Te 4+ 4.63 Se 4+ 0.30 As 5+ 0.06 S 6+ 0.01 ) Σ5.00 O 16 7H 2 O. Ozernovskite is monoclinic, C2/c, a 25.923(3), b 10.4192( 14), c 7.902(1) Å, β 93.415(4)°, V 2130.5(5)Å 3 , and Z = 4.The