Thermal expansion of new arsenate minerals, bradaczekite, NaCu4(AsO4)3, and urusovite, Cu(AsAlO5)
- 46 Downloads
Thermal behavior of two new exhalation copper-bearing minerals, bradaczekite and urusovite, from the Great Tolbachik Fissure Eruption (1975–1976, Kamchatka Peninsula, Russia) has been studied by X-ray thermal analysis within the range 20–700°C in air. The following major values of the thermal expansion tensor have been calculated for urusovite: α11 = 10, α22 = αb = 7, α33 = 4, αV = 21 × 10−6°C−1, μ = c∧α33 = 49° and bradaczekite: α11aver = 23, α22 = 8, α33aver = 6 × 10−6°C−1, μ(c∧α33) = 73°. The sharp anisotropy of thermal deformations of these minerals, absences of phase transitions, and stability of the minerals in the selected temperature range corresponding to conditions of their formation and alteration during the posteruption period of the volcanic activity are established.
KeywordsThermal Expansion Thermal Deformation Kamchatka Peninsula Monoclinic Unit Cell Arsenate Mineral
Unable to display preview. Download preview PDF.
- 2.S. K. Filatov, High-Temperature Crystal Chemistry (Nedra, Leningrad, 1990) [in Russian].Google Scholar
- 3.S. K. Filatov, D. S. Rybin, and L. P. Vergasova, “High-Temperature Expansion of bradaczekite, NaCu4(AsO4)3,” in Proceedings of International Conference on Crystal Chemistry and Spectroscopy” (Inst. Geol. Geochem., Ural Division, Russian Acad. Sci., Yekaterinburg, 2007), pp. 109–110.Google Scholar
- 5.S. V. Krivovichev, A. V. Molchanov, and S. K. Filatov, “Crystal Structure of Urusovite Cu[AlAsO5]: A New Type of a Tetrahedral Aluminoarsenate Polyanion,” Crystallogr. Reports 45, 793–797 (2000).Google Scholar
- 6.S. V. Krivovichev, S. K. Filatov, and P. K. Burns, “Jahn-Teller Distortion of Copper Polyhedron in Structural Type of Allyuaudite: Crystal Structure of Bradaczekite, NaCu4(AsO4)3,” Zap. Vseross. Mineral. O-va 130(5), 1–8 (2001).Google Scholar
- 7.The Great Fissure Tolbachik Eruption. Kamchatka 1975–1976, Ed. by S. A. Fedotov (Nauka, Moscow, 1984) [in Russian].Google Scholar
- 10.D. S. Rybin, S. K. Filatov, and L. P. Vergasova, “High-Temperature X-Ray Diffraction of Urusovite, Cu(AsAlO5),” in Proceedings of International Conference on Crystal Chemistry and X-Ray Diffraction of Minerals (Inst. Mineral., Ural Division, Russian Acad. Sci., Miass, 2007), pp. 228–231.Google Scholar
- 11.L. P. Vergasova, S. K. Filatov, and V. V. Dunin-Barkovskaya, “Posteruptive Activity of the First Cone of GFTE and Recent Volcanogenic Formation of Bauxites,” Vulkanol. Seismol., No. 2, 55–77 (2007).Google Scholar
- 12.L. P. Vergasova, S. K. Filatov, M. G. Gorskaya, A. A. Molchanov, S. V. Krivovichev, and V. V. Ananiev, “Urusovite, Cu[AlAsO5], a New Mineral from the Tolbachik Volcano, Kamchatka, Russia,” Eur. J. Miner. 12(5/6), 1041–1044 (2002).Google Scholar