Parageorgbokiite, β-Cu5O2(SeO3)2Cl2, a new mineral species from volcanic exhalations, Kamchatka Peninsula, Russia
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Parageorgbokiite, β-Cu5O2(SeO3)2Cl2, has been found at the second cinder cone of the Great Fissure Tolbachik Eruption, Kamchatka Peninsula, Russia. Ralstonite, tolbachite, melanothallite, chalcocyanite, euchlorine, Fe oxides, tenorite, native gold, sophiite, Na, Ca, and Mg sulfates, cotunnite, and some copper oxoselenites are associated minerals. The estimated temperature of the mineral formation is 400–625°C. The color is green, with a vitreous luster; the streak is light green. The mineral is brittle, with the Mohs hardness ranging from 3 to 4. Cleavage is not observed. The calculated density is 4.70 g/cm3. Parageorgbokiite is biaxial (+); α = 2.05(1), β = 2.05(1), and γ = 2.08(1); 2V (meas.) is ∼03, and 2V (calc.) = 0(5)°. The optical orientation is X = a; other details remain unclear. The mineral is pleochroic, from grass green on X and Y to yellowish green on Z. The empirical formula calculated on the basis of O + Cl = 10 is Cu4.91Pb0.02O1.86(ScO3)2Cl2.14. The simplified formula is Cu5O2(ScO3)2Cl2. Parageorgbokiite pertains to a new structural type of inorganic compounds. Its name points out its dimorphism with georgbokiite, which was named in honor of G.B. Bokii, the prominent Russian crystal chemist (1909–2000).
KeywordsNative Gold Yellowish Green Kamchatka Peninsula Cinder Cone Grass Green
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- 3.S. V. Krivovichev and S. K. Filatov, Crystallochemistry of Minerals and Inorganic Compounds with Chains of Anion-Centered Tetrahedrons (St. Petersburg State Univ., St. Petersburg, 2001) [in Russian].Google Scholar
- 4.S. V. Krivovichev, S. K. Filatov, and P. K. Burns, “The Jahn-Teller Distortion of Coordination Polyhedrons in the Structural Type of Alluaudite: Crystalloid Structure of Bradachekite, NaCu4(AsO4)3,” Zap. Ross. Mineral. O-va 130(5), 1–8 (2001).Google Scholar
- 5.S. V. Krivovichev, G. L. Starova, and S. K. Filatov, “’Face-to-Face’ Relationships between Oxocentered Tetrahedra and Cation-Centered Tetrahedral Oxyanions in Crystal Structures of Minerals and Inorganic Compounds,” Mineral. Mag. 63, 263–266 (1999a).Google Scholar
- 8.L. P. Vergasova, S. V. Krivovichev, S. N. Britvin, et al., “Allochalcoselite—a New Mineral of Volcanic Exhalations (Kamchatka, Russia),” Zap. Ross. Mineral. O-va 134(3), 70–74 (2005).Google Scholar
- 9.L. P. Vergasova, S. V. Krivovichev, T. F. Semenova, et al., “Chloromenite, Cu9O2(SeO3)4Cl6, a New Mineral from the Tolbachik Volcano, Kamchatka, Russia,” Eur. J. Mineral. 11, 119–123 (1999a).Google Scholar
- 10.L. P. Vergasova, T. F. Semenova, S. K. Filatov, et al., “Ilinskite, NaCu5O2(SeO3)2Cl2: A New Mineral of Volcanic Exhalations,” Dokl. Akad. Nauk 353, 641–644 (1997) [Dokl. Earth Sci. 353A (3), 352–355 (1997)].Google Scholar
- 11.L. P. Vergasova, T. F. Semenova, S. K. Filatov, et al., “Georgbokiite, Cu5O2(SeO3)2Cl2): A New Mineral of Volcanic Exhalations,” Dokl. Akad. Nauk 364, 527–531 (1999b) [Dokl. Earth Sci. 364 (1), 134–138 (1999)].Google Scholar