Abstract
Verneite, Na2Ca3Al2F14, is a new mineral first discovered in fumarolic samples from both Hekla, Iceland and Vesuvius, Italy. Additional occurrences are so far from Eldfell and Fimmvörduhals, both on Iceland. Verneite is cubic, I213, a = 10.264(1) Å, V = 1081.4(3) Å3, Z = 4, and corresponds to the known synthetic compound. The empirical formula is Na2.01Ca2.82Al2.17F14.02 (scanning electron microscopy with energy dispersive spectrometer from an unpolished sample). It appears in crystals up to 20 μm in diameter, with {110}, {100}, and {111} as the main forms. In the crystal structure of its synthetic analogue, Na is coordinated by 7 F atoms in the form of a capped octahedron, Ca with 8 F atoms in the form of a bisdisphenoid, and Al with 6 F atoms in the form of an octahedron. The crystal structure of Na2Ca3Al2F14 contains sinuous chains of Ca coordination polyhedra interlacing with similarly sinuous chains of Na coordination polyhedra and forming together with them layers parallel to {100}. The intersecting layers parallel to three equivalent crystallographic planes form a three-dimensional mesh with Al coordinations imbedded in its holes. The characteristics of Ca coordinations in fluorides, as well as their relations to other ternary Na–Ca–Al fluorides are discussed. Verneite is named after Jules Verne.
Subject
Geology,Geotechnical Engineering and Engineering Geology
Reference32 articles.
1. Encrustations from three recent volcanic eruptions in Iceland: The 1963–1967 Surtsey, the 1973 Eldfell and the 1991 Hekla eruptions;Jakobsson;Fjölrit Náttúrufraedistofnunar,2008
2. Eldfellite, NaFe(SO4)2, a new fumarolic mineral from Eldfell volcano, Iceland
3. Heklaite, KNaSiF6, a new fumarolic mineral from Hekla volcano, Iceland
4. Jakobssonite, CaAlF5, a new mineral from fumaroles at the Eldfell and Hekla volcanoes, Iceland
5. LEONARDSENITE, MgAlF5(H2O)2, A NEW MINERAL SPECIES FROM ELDFELL VOLCANO, HEIMAEY ISLAND, ICELAND
Cited by
5 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献