No CrossRef data available.
Article contents
Pohlite, a new lead iodate hydroxide chloride from Sierra Gorda, Chile
Published online by Cambridge University Press: 16 November 2022
Abstract
The new mineral pohlite (IMA2022–043), Pb7(IO3)(OH)4Cl9, was found at La Compania mine, Sierra Gorda, Antofagasta Province, Antofagasta, Chile, where it occurs in cavities in an oxidised portion of a quartz vein in association with massive aragonite and anhydrite. Pohlite crystals are transparent, colourless to pale grey blades, up to 4 mm in length. The mineral has a white streak, adamantine lustre and is nonfluorescent. It is brittle with irregular, conchoidal fracture. The Mohs hardness is ~2½ and it has no cleavage. The calculated density is 5.838(2) g cm–3. Optically, the mineral is biaxial (+) with α < 2.01(est.), β = 2.02 (calc.), γ = 2.05 (calc.); 2V = 60(5)°; moderate r > v dispersion; orientation: Y ∧ a ≈ 20°, Z ∧ b ≈ 30°; and is nonpleochroic. The Raman spectrum exhibits bands consistent with IO3– and O–H. Electron microprobe analysis provided the empirical formula Pb6.74I1.00Cl9.29O6.71H4.23. The five strongest powder X-ray diffraction lines are [dobs Å(I)(hkl)]: 3.818(91)(023, 122, 1$\bar{2}$
1), 3.674(85)($\bar{1}\bar{2}$
1, $\bar{1}$
22, 200, 104), 3.399(47)($\bar{2}$
10, 210, $\bar{1}$
04), 2.378(100)(302, 041, $\bar{2}$
24) and 1.9943(45)(multiple). Pohlite is triclinic, P$\bar{1}$
, a = 7.3366(5), b = 9.5130(9), c = 16.2434(15) Å, α = 81.592(7), β = 84.955(7), γ = 89.565(6)°, V = 1117.13(17) Å3 and Z = 2. The structure of pohlite (R1 = 0.0328 for 3394 I > 2σI) contains two types of clusters, a [Pb4(OH)3]5+ cluster formed by short Pb–O bonds and a [Pb3(OH)(IO3)]28+ ‘double cluster’ formed by short I–O bonds and short- to medium-length Pb–O bonds. Long Pb–Cl and I–Cl bonds link the clusters together in three dimensions.
Keywords
- Type
- Article
- Information
- Copyright
- Copyright © The Author(s), 2022. Published by Cambridge University Press on behalf of The Mineralogical Society of Great Britain and Ireland
Footnotes
Associate Editor: David Hibbs
References
Bindi, L., Welch, M.D., Bonazzi, P., Pratesi, G. and Menchetti, S. (2008) The crystal structure of seeligerite, Pb3IO4Cl3, a rare Pb–I-oxychloride from the San Rafael mine, Sierra Gorda, Chile. Mineralogical Magazine, 72, 771–783.CrossRefGoogle Scholar
Boric, R., Diaz, F. and Maksaev, V. (1990) Geologia y yacimientos metaliferos de la region de Antofagasta. Servicio Nacional de Geologia y Mineria Boletin, 40, 246 pp.Google Scholar
Brese, N.E. and O'Keeffe, M. (1991) Bond-valence parameters for solids. Acta Crystallographica, B47, 192–197.CrossRefGoogle Scholar
Cooper, M.A., Hawthorne, F.C., Merlino, S., Pasero, M. and Perchiazzi, N. (1999) Stereoactive lone-pair behavior of Pb in the crystal structure of bideauxite; Pb2+2Ag+Cl3F(OH). The Canadian Mineralogist, 37, 915–921.Google Scholar
Ferraris, G. and Ivaldi, G. (1988) Bond valence vs. bond length in O⋅⋅⋅O hydrogen bonds. Acta Crystallographica, B44, 341–344.CrossRefGoogle Scholar
Gagné, O.C. and Hawthorne, F.C (2015) Comprehensive derivation of bond-valence parameters for ion pairs involving oxygen. Acta Crystallographica, B71, 562–578.Google Scholar
Girase, K., Sawant, D.K., Patil, H.M. and Bhavsar, D.S. (2013) Thermal, FTIR and Raman spectral analysis of Cu (II)-doped lead iodate crystals. Journal of Thermal Analysis and Calorimetry, 111, 267–271.CrossRefGoogle Scholar
Jensen, J.O. (2002) Vibrational frequencies and structural determinations of Pb4(OH)44+. Journal of Molecular Structure: THEOCHEM, 587, 111–121.CrossRefGoogle Scholar
Kampf, A.R., Harlow, G.E. and Ma, C. (2022a) Pohlite, IMA 2022-043. CNMNC Newsletter 69. Mineralogical Magazine, 86, 988–992, https://doi.org/10.1180/mgm.2022.115.Google Scholar
Kampf, A.R., Hughes, J.M., Nash, B.P. and Marty, J. (2022b) Nitroplumbite, [Pb4(OH)4](NO3)4, a new mineral cubane-like [Pb4(OH)4]4+ clusters from the Burro mine, San Miguel County, Colorado, USA. The Canadian Mineralogist, 60, 787–795.CrossRefGoogle Scholar
Kampf, A.R., Smith, J.B., Hughes, J.M., Ma, C. and Emproto, C. (2022c) Cubothioplumbite, IMA 2021-091. CNMNC Newsletter 65. Mineralogical Magazine, 86, 354–358, https://doi.org/10.1180/mgm.2022.14Google Scholar
Kampf, A.R., Smith, J.B., Hughes, J.M., Ma, C. and Emproto, C. (2022d) Hexathioplumbite, IMA 2021-092. CNMNC Newsletter 65; Mineralogical Magazine, 86, 354–358, https://doi.org/10.1180/mgm.2022.14Google Scholar
Kampf, A.R., Smith, J.B., Hughes, J.M., Ma, C. and Emproto, C. (2022e) Hayelasdiite, IMA 2022-021. CNMNC Newsletter 68. Mineralogical Magazine, 86, 854–859, https://doi.org/10.1180/mgm.2022.93.Google Scholar
Kampf, A.R., Smith, J.B., Hughes, J.M., Ma, C. and Emproto, C. (2022f) Finescreekite, IMA 2022-030. CNMNC Newsletter 68. Mineralogical Magazine, 86, 854–859, https://doi.org/10.1180/mgm.2022.93Google Scholar
Kolitsch, U. and Tillmanns, E. (2003) The crystal structure of anthropogenic Pb2(OH)3(NO3), and a review of Pb-(O,OH) clusters and lead nitrates. Mineralogical Magazine, 67, 79–93.CrossRefGoogle Scholar
Malcherek, T. and Schlüter, J. (2006) Cu3MgCl2(OH)6 and the bond-valence parameters of the OH–Cl bond. Acta Crystallographica, B63, 157–160.Google Scholar
Mandarino, J.A. (2007) The Gladstone–Dale compatibility of minerals and its use in selecting mineral species for further study. The Canadian Mineralogist, 45, 1307–1324.CrossRefGoogle Scholar
Pohl, D.C. (1986) Supergene gold transport in bromide groundwater (abstract). Geological Society of America, Abstracts with Programs, pp. 720.Google Scholar
Rouse, R.C. and Peacor, D.R. (1994) Maricopaite, an unusual lead calcium zeolite with an interrupted mordenite-like framework and intrachannel Pb4 tetrahedral clusters. American Mineralogist, 79, 175–184.Google Scholar
Rumsey, M.S., Welch, M.D., Kleppe, A.K. and Spratt, J. (2017) Siidraite, Pb2Cu(OH)2I3, from Broken Hill, New South Wales, Australia: the third halocuprate(I) mineral. European Journal of Mineralogy, 29, 1027–1030.CrossRefGoogle Scholar
Schellenschläger, V., Pracht, G. and Lutz, H.D. (2001) Single-crystal Raman studies on nickel iodate dihydrate, Ni(IO3)2⋅2H2O. Journal of Raman Spectroscopy, 32, 373–382.CrossRefGoogle Scholar
Sheldrick, G.M. (2015a) SHELXT – Integrated space-group and crystal-structure determination. Acta Crystallographica, A71, 3–8.Google Scholar
Sheldrick, G.M. (2015b) Crystal structure refinement with SHELX. Acta Crystallographica, C71, 3–8.Google Scholar
Welch, M.D., Hawthorne, F.C., Cooper, M.A. and Kyser, T.K. (2001) Trivalent iodine in the crystal structure of schwartzembergite, Pb2+5I3+O6H2Cl3. The Canadian Mineralogist, 39, 785–795.CrossRefGoogle Scholar
Welch, M.D., Rumsey, M.S. and Kleppe, A.K. (2016) A naturally-occurring new lead-based halocuprate(I). Journal of Solid State Chemistry, 238, 9–14.CrossRefGoogle Scholar
Williams, W.C. (1992) Magmatic and Structural Controls on Mineralization in the Paleocene Magmatic Arc Between 22°40′ And 23°45′ South Latitude, Antofagasta, II Region, Chile. Ph.D. Dissertation, University of Arizona, USA.Google Scholar
Kampf et al. supplementary material
Kampf et al. supplementary material 1
File
623.3 KB
Kampf et al. supplementary material
Kampf et al. supplementary material 2
PDF
146.5 KB
Kampf et al. supplementary material
Kampf et al. supplementary material 3
PDF
61 KB