Skip to main content Accessibility help
×
Home

Uranium and uranyl luminescence in agate/chalcedony

  • Jens Götze (a1), Michael Gaft (a2) and Robert Möckel (a3)

Abstract

A systematic investigation of agates from different occurrences in Europe, Northern and Southern America reveals that macrocrystalline quartz and chalcedony within them have an unusually high uranium content. Whereas agates may contain >70 ppm of U, quartz from magmatic and metamorphic rocks as well as pegmatite quartz commonly exhibit U concentrations at sub-ppm levels. Spatially resolved trace-element analyses by laser ablation inductively coupled plasma mass spectrometry show that the distribution of U within the agate samples is heterogeneous and coincides with the structural banding. The results indicate that U is incorporated into agate as uranyl ions. These ions, which are bound to the silica surface, are interpreted to originate from the parallel accumulation of Si and U by alteration processes of surrounding host rocks during agate formation.

The uranyl ion is the cause of greenish photoluminescence (PL) in agate, which can only be excited by short wavelengths (<300 nm). The green PL is due to the electron transition from an excited to a ground state of the uranyl ion and is shown by a typical emission line at ∼500 nm accompanied by several equidistant lines. These are due to the harmonic vibration of oxygen atoms along the uranyl axis. Luminescence can be detected in samples with a U content down to the 1 ppm level.

Copyright

Corresponding author

Footnotes

Hide All

Present address: TU Bergakademie Freiberg, Institute of Mineralogy, Brennhausgasse 14, D-09596 Freiberg, Germany

Footnotes

References

Hide All
Blankenburg, H.-J., Gotze, J. and Schulz, H. (1994) Quarzrohstoffe. Deutscher Verlag fur Grundstoffindustrie, Leipzig-Stuttgart, Germany, 296 pp.
Clarke, F.W. and Washington, H.S. (1924) The Composition of the Earth's Crust. Geological, U.S. Survey, Professional Paper, 127. Geological Survey, Reston, Virginia, USA, 117 pp.
DeNeufville, IP., , Kasdan, A. and Chimenti, RJ. (1981) Selective detection of uranium by laser-induced fluorescence: a potential remote-sensing technique: 1. Optical characteristics of uranyl geologic targets. Applied Optics, 20, 12791296.
Gaillou, E., Delaunay, A., Rondeau, B., Bouhnik-le-Coz, M., Fritsch, E., Cornen, G. and Monnier, C. (2008) The geochemistry of gem opals as evidence of their origin. Ore Geology Reviews, 34, 113126.
Gerler, J. (1990) Geochemische Untersuchungen an hydrothermalen, metamorphen, granitischen und p egmatitis chert Quarz en und deren Flussigkeitseinschlussen. PhD thesis. University of Gottingen, Germany.
Glinka, Yu.D. and Krak, T.B. (1995) Luminescence spectra of uranyl ions adsorbed on disperse SiO2surfaces. Physical Review B, 52, 1498514994.
Gorobets, B.S. and Rogojine, A.A. (2002) Luminescent Spectra of Minerals. RPC VIMS, Moscow, 300 pp.
Gotze, J. (2009) Chemistry, textures and physical properties of quartz—geological interpretation and technical application. Mineralogical Magazine, 73, 645671.
Gotze, J. (2011) Agate—fascination between legend and science. Pp. 19133 in: Agates III (J. Zenz, editor). Bode-Verlag, Salzhemmendorf, Germany.
Gotze, J., Plotze, M., Fuchs, H. and Habermann, D. (1999) Defect structure and luminescence behaviour of agate—results of electron paramagnetic resonance (EPR) and cathodoluminescence (CL) studies. Mineralogical Magazine, 63, 149163.
Gotze, J., Tichomirowa, M., Fuchs, H., Pilot, J. and Sharp, Z. (2001) Geochemistry of agates: a trace element and stable isotope study. Chemical Geology, 175, 523541.
Gotze, J., Plotze, M., Graupner, T., Hallbauer, D.K. and Bray, C. (2004) Trace element incorporation into quartz: a combined study by ICP-MS, electron spin resonance, cathodoluminescence, capillary ion analysis and gas chromatography. Geochimica et Cosmochimica Ada, 68, 37413759.
Gotze, J., Mockel, R., Kempe, U., Kapitonov, I. and Vennemann, T. (2009) Origin and characteristics of agates in sedimentary rocks from the Dryhead area, Montana/USA. Mineralogical Magazine, 73, 673690.
Gotze, J., Schron, W., Mockel, R. and Heide, K. (2012a) The role of fluids in the formation of agate. Geochemistry, 72, 283286.
Gotze, J., Nasdala, L., Kempe, U., Libowitzky, E., Rericha, A. and Vennemann, T. (2012) Origin of black colouration in onyx agate from Mali. Mineralogical Magazine, 76, 115127.
Harder, H. (1993) Agates-formation as a multi component colloid chemical precipitation at low temperatures. Neues Jahrbuch Mineralogie Monatshefte, HI, 31-48.
Hollocher, and Ruiz, (1995) Major and trace element determinations on NIST glass standard reference materials 611, 612, 614 and 1834 by inductively coupled plasma-mass spectrometry. Geostandards Newsletter, 19(1), 27-34.
Holzhey, G. (1995) Herkunft und Akkumulation des SiO2 in Rhyolithkugeln aus Rotliegendvulkaniten des Thiiringer Waldes. Geowissenschaftliche Mitteilungen von Thuringen, 3, 3159.
Kobyshev, G.I. (1961) Luminescence of surface-active crystals adsorbing uranyl ions (in Russian). Izvestiya Akademii Nauk SSSR, Seria physika, 25(4), 542-545.
Krickl, R., Nasdala, L., Gotze, J. and Grambole, D. (2008) Alteration of SiO2 caused by natural and artificial alpha-irradiation. European Journal of Mineralogy, 20, 517522.
Landmesser, M. (1984) Das Problem der Achatgenese. Mitteilungen Pollichia, 72(5), 5-137.
Lehmann, G. and Bambauer, H.U. (1973) Quarzkristalle und ihre Farben. Angewandte Chemie, 85, 281289.
Lopez, M. and Birch, DJ.S. (1996) Uranyl photophysics on colloidal silica: an alternative luminescence-enhancing medium for uranyl assay. Analyst, 121, 905908.
Lyons, W.H., Glascock, M.D. and Mehringer Jr., PJ. (2003) Silica from sources to site: ultraviolet fluorescence and trace elements identify cherts from Lost Dune, southeastern Oregon, USA. Journal of Archaeological Science, 30, 11391159.
Marfunin, A.S. (1979) Spectroscopy, Luminescence and Radiation Centres in Minerals. Springer, Berlin, 352 pp.
Matteson, S., Avara, M.J., Nguyen, C.V. and Kim, S.H. (2005) RBS characterization of uranium in flint and chert. Nuclear Instruments and Methods in Physics Research, B 241, 465469.
Matysova, P., Gotze, J., Leichmann, J., Skoda, R., Strnad, L. and Drahota, P. (2013) CL as a tool for identification of diagenetic changes in Permian silicified wood—evidence of U and V mobility. Conference on Raman and Luminescence Spectroscopy in the Earth Sciences (CORALS-2013), Book of abstracts, 77-78.
Mockel, R. and Gotze, J. (2007) Achate aus sachsischen Vulkaniten des Erzgebirgischen Beckens. Veroffentlichung Museum Naturkunde Chemnitz, 30, 2560.
Mockel, R., Gotze, J., Sergeev, S.A., Kapitonov, I.N., Adamskaya, E.V., Goltsin, N.A. and Vennemann, T. (2009) Trace-element analysis by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS): a case study for agates from Nowy Kosciol, Poland. Journal of Siberian Ferderal University, Engineering & Technologies, 2,123-138.
Monecke, T., Bombach, G., Klemm, W., Kempe, U., Gotze, J. and Wolf, D. (2000) Determination of trace elements in quartz standard UNS-SpS and in natural quartz by ICP-MS. Geostandards Newsletter, 24, 7381.
Moxon, T. (1996) Agate: Microstructure and Possible Origin. Terra Publications, Doncaster, UK, 106 pp.
Moxon, T. (2009) Studies on Agate—Microscopy, Spectroscopy, Growth, High Temperature and Possible Origin. Terra Publications, Doncaster, UK, 102 pp.
Owen, M.R. (1988) Radiation-damage halos in quartz. Geology, 16, 529532.
Pabian, R.K. and Zarins, A. (1994) Banded agates—Origins and inclusions. Educational Circular No. 12, University of Nebraska, Lincoln, USA, 32 pp.
Porter, R.A. and Weber Jr., WJ. (1971) The interaction of silicic acid with iron(III) and uranyl ions in dilute aqueous solution. Journal of Inorganic and Nuclear Chemistry, 33, 24432449.
Schron, W., Oppermann, H., Rosier, HJ. and Brand, P. (1988) Fest-Gas-Reaktionen als Ursache geo-und kosmogeochemischer Mobilisierungs-und Anreicherungsprozesse. Chemie der Erde, 48, 3554.
Walger, E. (1954) Das Vorkommen von Uruguay-Achaten bei Flonheim in Rheinhessen, seine tektonische Auswertung und seine Bedeutung fur die Frage nach der Achatbildung. Jahresbericht Mitteilungen Oberrheinische Geologische
Zielinski, R.A. (1979) Uranium mobility during interaction of rhyolitic obsidian, perlite and felsite with alkaline carbonate solution: T = 120°C, P = 210 kg/cm2 . Chemical Geology, 27, 4763.
Zielinski, R.A. (1982) Uraniferous opal, Virgin Valley, Nevada: Conditions of formation and implications for uranium exploration. Journal of Geochemical Exploration, 16, 197216.

Keywords

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed