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Growth and dissolution features in hydrothermal vein minerals – a study of Colombian emeralds using SEM and element-distribution mapping

Published online by Cambridge University Press:  14 July 2025

Gerhard Franz Open the ORCID record for Gerhard Franz [Opens in a new window] ,
Ferry Schiperski ,
Vladimir Khomenko ,
Ulrich Gernert  and
Jörg Nissen
Gerhard Franz*
Affiliation:
Fachgebiet Angewandte Geochemie, Technische Universität Berlin, Berlin, Germany
Ferry Schiperski
Affiliation:
Fachgebiet Angewandte Geochemie, Technische Universität Berlin, Berlin, Germany
Vladimir Khomenko
Affiliation:
M.P. Semenenko Institute of Geochemistry, Mineralogy and Ore Formation, The National Academy of Sciences of Ukraine, Kyiv, Ukraine;
Ulrich Gernert
Affiliation:
Zentraleinrichtung Elektronenmikroskopie, Technische Universität Berlin, Berlin, Germany
Jörg Nissen
Affiliation:
Zentraleinrichtung Elektronenmikroskopie, Technische Universität Berlin, Berlin, Germany
*
Corresponding author: Gerhard Franz; Email: gefra548@gmail.com
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Abstract

Beryl crystals from hydrothermal veins in the Colombian emerald mining district, were examined to understand their growth and dissolution processes. Chemical analysis reveals minor substitution of Al by Na, Mg and the colouring elements V, Cr and Fe. Growth features include characteristic indentations on (0001) and a ridge-and-valley structure on the second-order prism, which is also observed on rare conical growth faces. Zoning is the primary internal growth feature, investigated in cross sections parallel to the main growth directions, the a- and c-axes of beryl. All crystals show sector zoning, with enrichment of Na and Mg in the c-sector, whereas Al and most of the trace elements measured are concentrated in the a-sector. H2O and CO2 molecules in the crystal structure were identified by infrared spectroscopy. Two types of H2O are present, with the H–H vector aligned (type I) and perpendicular (type II) to the c-axis, with H2O II predominant in the c-sector. CO2 is present in both sectors, decreasing from core to rim, and is higher in the a-sector. Variable sector boundaries suggest irregular changes in the growth rate in the two growth directions. The substitution (VIMg+channelNa)c-sector = (VIAl+channel□)a-sector creates a pattern of stripes, originating at the steps of the sector boundaries. Etch pits as a result of dissolution are arranged in chains, typically forming etching channels, but the overall amount of dissolution is minor. The arrangement of the etch pits indicates that they formed on dislocation bundles, which originate at the sector boundaries. The observations indicate rapid crystallisation with skeletal growth in [0001] is responsible for the distribution of elements in sectors, and are consistent with a closed-system behaviour in the veins.

Keywords

berylemeraldcompositional zoningetch pitsgrowth featuresconical growthscanning electron microscopy

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Article
Information
Mineralogical Magazine , First View , pp. 1 - 16
Copyright
© The Author(s), 2025. Published by Cambridge University Press on behalf of The Mineralogical Society of the United Kingdom and Ireland.

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Footnotes

Guest Editor: Barbara Dutrow

This paper is part of a collection in tribute to the work of Edward Grew at 80

References

Aurisicchio, C., Fioravanti, G., Grubessi, O. and Zanazzi, P.F. (1988) Reappraisal of the crystal chemistry of beryl. American Mineralogist, 75, 826–837.Google Scholar
Bartoshinskiy, Z.V., Matkovskiy, O.I. and Srebrodolskiy, B.I. (1969) Accessory beryl from chamber pegmatites of Ukraine. Mineralogical Sbornik, 23, 382–397 [in Russian].Google Scholar
Beig, M.S. and Lüttge, A. (2006) Albite dissolution kinetics as a function of distance from equilibrium: Implications for natural feldspar weathering. Geochimica and cosmochimica acta, 70, 1402–1420. doi:10.1016/j.gca.2005.10.035.Google Scholar
Demianets, L.N., Ivanov-Shitz, A.K. and Gainutdinov, R.V. (2006) Hydrothermal growth of beryl single crystals and morphology of their singular faces. Inorganic materials, 42, 989–995. doi:10.1134/S0020168506090111.Google Scholar
Dem’yanets, L.N. and A.K, Ivanov-Schitz. (2009) Beryl: Regeneration crystal growth and morphology of regeneration surfaces. Journal of Surface Investigation, X-ray, Synchrotron and Neutron Techniques, 3, 881–887, doi:10.1134/S1027451009060068.Google Scholar
Franz, G., Vyshnevskyi, O., Taran, M., Khomenko, V., Wiedenbeck, M., Schiperski, F. and Nissen, J. (2020) A new emerald occurrence from Kruta Balka, Western Peri-Azovian region, Ukraine: Implications for understanding the crystal chemistry of emerald. American Mineralogist, 105, 162–181. doi:org/0021-8898/81/040241-06501.00.Google Scholar
Franz, G., Vyshnyevskyi, O., Khomenko, V., Lyckberg, P., Wiedenbeck, M. and Gernert, U. (2023) Etch pits in heliodor from the Volyn pegmatites, NW Ukraine – a diagnostic feature. Gems & Gemology, 59, 324–339, doi:10.5741/GEMS.59.3.324.Google Scholar
Franz, G., Schiperski, F., Khomenko, V., Gernert, U. and Nissen, J. (2025) Columbian emeralds – internal and external growth and dissolution features (ex 2023.021). GFZ Data Services. doi:10.5880/fidgeo.2025.006.Google Scholar
Graziani, G., Scandale, E. and Zarka, A. (1981) Growth of a beryl single crystal – history of the development and the genetic medium. Journal of Applied Crystallography, 14, 241, 246.Google Scholar
Grew, E.S. (2002) Mineralogy, Petrology and Geochemistry of Beryllium: An Introduction and List of Beryllium Minerals. Reviews in Mineralogy and Geochemistry, 50, 1-76.Google Scholar
Groat, L.A., Giuliani, G., Marschall, D.D. and Turner, D. (2008) Emerald deposits and occurrences: A review. Ore Geology Reviews, 14, 87–112, doi:10.1016/j.oregeorev.2007.09.003Google Scholar
Henry, D.J. and Dutrow, B.L. (1996) Metamorphic tourmaline and its petrologic applications. Pp. 505–557 in: Boron: Mineralogy, Petrology, and Geochemistry (Grew, E.S. and Anovitz, L.M., editors). Reviews in Mineralogy, Volume 33, Mineralogical Society of America, Washington D.C.Google Scholar
Henry, R.E., Groat, L.A., and Evans, R.J. (2022) Crystal-chemical observations and the relation between sodium and H2O in different beryl varieties. The Canadian Mineralogist, 60, 626–675, doi: 10.3749/canmin.2100050.Google Scholar
Herzberg, C. (1945) Infrared and Raman Spectra of Polyatomic Molecules. Vol. 2, van Nostrand, Inc. New York.Google Scholar
Khomenko, V. and Langer, K. (2005) Carbon oxides in cordierite channels: Determination of CO2 isotopic species and CO by single crystal IR spectroscopy. American Mineralogist, 90, 1913–1917. doi: 10.2138/am.2005.1963.Google Scholar
Kohn, M. (2014) Geochemical zoning in metamorphic minerals. Treatise in Geochemistry, 3, 229–261.Google Scholar
Kohn, V., Alifirova, T., Daneu, N. Griffiths, T.A., Libowitzky, E., Linner, M., Ertl, A., Abart, R. and Habler, G. (2024) Directed growth of a sector-zoned garnet in a pegmatoid from the Bohemian Massif, Austria. Lithos, 466–467, 107461, doi:10.1016/j.lithos.2023.107461.Google Scholar
Kurumathoor, R. and Franz, G. (2018) Etch pits on beryl as indicators of dissolution behaviour. European Journal of Mineralogy, 30, 107–124.Google Scholar
Lefeuvre, B., Dubacq, B., Verlaguet, A., Herviou, C., Walker, S., Caron, B., Baxter, E. and Agard, P. (2024) Disentangling the compositional variations of lawsonite in blueschist-facies metasediments (Schistes Lustrés, W. Alps). Contributions to Mineralogy and Petrology, 179, 25, doi:10.1007/s00410-024-02104-5.Google Scholar
Libowitzky, E., and Rossman, G. R. (1997). An IR absorption calibration for water in minerals. American Mineralogist, 82, 1111–1115.Google Scholar
Loughrey, L., Groat, D., Jones, P., Millsteed, P. and Main, A. (2012) Emmaville-Torrington emerald deposit. Central European Journal of Earth Sciences, 4, 287–299 doi:10.2478/s13533-011-0056-9.Google Scholar
Loughrey, L., Marshall, D., Ihlen, P. and Jones, P. (2013) Boiling as a mechanism for colour zonations observed at the Byrud emerald deposit, Eidsvoll, Norway: fluid inclusion, stable isotope and Ar–Ar studies. Geofluids, 13, 542–558.Google Scholar
Lu, D., Jiang, Q., Ma, X., Zhang, Q., Fu, X. and Fan, L. (2022) Defect-related etch pits on crystals and their utilization. Crystals, 12, 1549.Google Scholar
Lüttge, A. (2005) Etch pit coalescence, surface area, and overall mineral dissolution rates. American Mineralogist, 90, 1776–17873. doi: 10.2138/am.2005.1734.Google Scholar
Philpotts, A. and Ague, J. (2009) Principles of Igneous and Metamorphic Petrology. 2nd ed, Cambridge University Press, Cambridge, UK, ISBN 978-0-52188006-0.Google Scholar
Pignatelli, I., Guiliani, G., Ohnenstetter, D., Agrosi, G., Mathieu, S., Morlot, C. and Branquet, Y. (2015) Colombian trapiche emeralds: Recent advances in understanding their formation. Gems & Gemology, 51, 222–259, doi:10.5741/GEMS.51.3.222.Google Scholar
Pignatelli, I., Morlot, C., Salsi, L., Giuliani, G. and Martayan, G. (2022) Colombian emerald oddities: Review and formation mechanisms. The Journal of Gemmology, 38, 26–43, doi:10.3190/jgeosci.314.Google Scholar
Renfro, N., Smith, T., Koivula, J.I., McClure, S.F., Schumacher, K., and Shigley, J.E. (2023) Micro-features of beryl. Gems & Gemology, 59, 484–485, doi:10.5741/GEMS.59.4.484.Google Scholar
Saeseaw, S., Refro, N.D., Palke, A.C., Sun, Z. and McClure, S.F. (2019) Geographic origin determination of emerald. Gems & Gemology, 55, 614–646, doi:10.5741/GEMS.55.4.614.Google Scholar
Scandale, E., Lucchesi, S. and Graziani, G. (1990) Growth defects and growth marks in pegmatitic beryls. European Journal of Mineralogy, 2, 305–311.Google Scholar
Schmetzer, K. and Martayan, G. (2023) Morphology of Colombian emerald: Some less common cases and their growth and dissolution history. Gems & Gemology, 59, 46–71, doi:10.5741/GEMS.59.1.46.Google Scholar
Schwarz, D. and Schmetzer, K. (2002) The definition of emerald: The green variety of beryl colored by chromium and/or vanadium. Pp. 74–78 in: Emeralds of the World. ExtraLapis English No. 2: The Legendary Green Beryl. Lapis International, LLC, East Hampton, USA.Google Scholar
Sunagawa, I. (2005) Crystals – Growth, Morphology, and Perfection. Cambridge University Press, Cambridge UK, ISBN- 13 978-0-511-11345-1, pp. 308.Google Scholar
Sunagawa, I. and Urano, A. (1999) Beryl crystals from pegmatites: morphology and mechanism of crystal growth. Journal of Gemmology, 26, 521–553.Google Scholar
Van Hinsberg, V.J., Schumacher, J.C., Kearnsi, S., Mason, P.R.D. and Franz, G. (2006) Hour glass zoning in metamorphic tourmaline and resultant major and trace element fractionation. American Mineralogist, 91, 717–728.Google Scholar
Wood, D.L. and Nassau, K. (1967) Infrared spectra of foreign molecules in beryl. The Journal of Chemical Physics, 47, 2220–2228.Google Scholar