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Fire agate from the Deer Creek deposit (Arizona, USA) – new insights into structure and mineralogy

Published online by Cambridge University Press:  05 February 2020

Lucyna Natkaniec-Nowak
Affiliation:
Faculty of Geology, Geophysics, and Environmental Protection, AGH University of Science and Technology, Krakow30-059, 30 Mickiewicz Av., Poland
Magdalena Dumańska-Słowik*
Affiliation:
Faculty of Geology, Geophysics, and Environmental Protection, AGH University of Science and Technology, Krakow30-059, 30 Mickiewicz Av., Poland
Adam Gaweł
Affiliation:
Faculty of Geology, Geophysics, and Environmental Protection, AGH University of Science and Technology, Krakow30-059, 30 Mickiewicz Av., Poland
Anna Łatkiewicz
Affiliation:
Institute of Geological Sciences, Jagiellonian University, Krakow30-387, 3a Gronostajowa str., Poland
Joanna Kowalczyk-Szpyt
Affiliation:
Faculty of Geology, Geophysics, and Environmental Protection, AGH University of Science and Technology, Krakow30-059, 30 Mickiewicz Av., Poland
Anna Wolska
Affiliation:
Faculty of Geography and Biology, Pedagogical University, Krakow30-084, 2 Podchorążych str., Poland
Stanislava Milovská
Affiliation:
Earth Science Institute, Slovak Academy of Sciences, 1 Ďumbierska str., 974 11 Banská Bystrica, Slovakia.
Jarmila Luptáková
Affiliation:
Earth Science Institute, Slovak Academy of Sciences, 1 Ďumbierska str., 974 11 Banská Bystrica, Slovakia.
Karolina Ładoń
Affiliation:
Faculty of Geology, Geophysics, and Environmental Protection, AGH University of Science and Technology, Krakow30-059, 30 Mickiewicz Av., Poland
*
*Author for correspondence: Magdalena Dumańska-Słowik, Email: [email protected]

Abstract

Fire agates from Deer Creek are highly appreciated gemstones due to the presence of optical phenomena and rainbow colours that cause fiery effects to be observed on their characteristic brown base. The specific morphology of poorly ordered chalcedony (crystallinity index = 0.1–1.5) with an admixture of mogánite (av. 6.6%), micro-quartz and opal-C forming a colloform texture seems to be responsible for the presence of fire effect in these agates. The multi-layered silica spheroidal forms (‘bubble’-like structure), already noted in hand specimens, could be the centres of reflection and interference of white light. Numerous, microscopic inclusions of Fe and Ti compounds randomly scattered within some silica zones, together with microstructural features of agate, could determine the colour and size of the domains with the optical effect. Deer Creek fire agates form veins within their host volcanic rocks. The silica mineralisation filling the network of fissures in the host rocks was supplied cyclically with aqueous fluids of varying composition, enriched periodically in CO2, Fe, Ti, Mn, Zn and Ca. As a result, the red-brown colour of fire agates was created by scattered pigments of tiny iron oxides (magnetite, maghemite) and titanium oxides (rutile, anatase) within the silica matrix. The precipitation of strongly disordered silica with a characteristic colloform texture is diagnostic for boiling processes in this area.

Type
Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland, 2020

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Footnotes

Associate Editor: Martin Lee

References

Bish, D.L. and Reynolds, R.C. Jr. (1989) Sample preparation for X-ray diffraction. Pp. 7399 in: Modern Powder Diffraction (Bish, D. L. and Post, J.E., editors). Reviews in Mineralogy 20. Mineralogical Society of America, Washington, DC.CrossRefGoogle Scholar
Brown, D.S. (1993) Mineral Appraisal of the Coronado National Forest Part 9, Galiuro Mountains Unit, Graham County, Arizona. Denver, Colorado, USA, 41 pp.Google Scholar
Constantina, C. and Moxon, T. (2010) Agates from Gurasada, southern Apuseni Mountains, Romania: An XRD and thermogravimetric study. Carpathian Journal of Earth and Environmental Sciences, 5, 8999.Google Scholar
Dong, G., Morrison, G. and Jaireth, S. (1995) Quartz textures in epithermal veins, Queensland – Classification, origin, and implication. Economic Geology, 90, 18411856.CrossRefGoogle Scholar
Dumańska-Słowik, M., Natkaniec-Nowak, L., Kotarba, M.J., Sikorska, M., Rzymetka, J.A., Loboda, A. and Gaweł, A. (2008) Mineralogical and geochemical characterization of the “bituminous” agates from Nowy Kościół (Lower Silesia, Poland). Neues Jahrbuch fur Mineralogie, Abhandlungen, 184, 255268.Google Scholar
Dumańska-Słowik, M., Natkaniec-Nowak, L., Wesełucha-Birczyńska, A., Gaweł, A., Lankosz, M. and Wróbel, P. (2013) Agates from Sidi Rahal, in the atlas Mountains of Morocco: Gemological characteristics and proposed origin. Gems and Gemology, 49, 148159.CrossRefGoogle Scholar
Dumańska-Słowik, M., Powolny, T., Sikorska-Jaworowska, M., Gaweł, A., Kogut, L. and Poloński, K. (2018) Characteristics and origin of agates from Płóczki Górne (Lower Silesia, Poland): A combined microscopic, micro-Raman, and cathodoluminescence study. Spectrochimica Acta – Part A: Molecular and Biomolecular Spectroscopy, 192, 615.Google ScholarPubMed
Flörke, O.W., Graetsch, H., Martin, B., Röller, K. and Wirth, R. (1991) Nomenclature of micro- and non-crystalline silica minerals, based on structure and microstructure. Neues Jahrbuch fur Mineralogie. Abhandlungen, 163, 1942.Google Scholar
Fournier, R.O. (1985) The behavior of silica in hydrothermal solutions. Reviews in Economic Geology, 2, 4561.Google Scholar
Götze, J., Nasdala, L., Kleeberg, R. and Wenzel, M. (1998) Occurrence and distribution of “moganite” in agate/chalcedony: A combined micro-Raman, Rietveld, and cathodoluminescence study. Contributions to Mineralogy and Petrology, 133, 96105.CrossRefGoogle Scholar
Götze, J., Möckel, J., Kempe, U., Kapitonov, I. and Vennemann, T. (2009) Characteristics and origin of agates in sedimentary rocks from the Dryhead area, Montana, USA. Mineralogical Magazine, 73, 673690.CrossRefGoogle Scholar
Götze, J., Nasdala, L., Kempe, U., Libowitzky, E., Rericha, A. and Vennemann, T. (2012) The origin of black colouration in onyx agate from Mali. Mineralogical Magazine, 76, 115127.CrossRefGoogle Scholar
Hanesch, M. (2009) Raman spectroscopy of iron oxides and (oxy)hydroxides at low laser power and possible applications in environmental magnetic studies. Geophysical Journal International, 177, 941948.CrossRefGoogle Scholar
Hardcastle, F.D. (2011) Raman spectroscopy of titania (TiO2) nanotubular water-splitting catalysts. Journal of the Arkansas Academy of Science, 65, 47.Google Scholar
Heaney, P.J. (1995) Moganite as an indicator for vanished evaporates: A testament reborn? Journal of Sedimentary Research A:, 65, 633638.Google Scholar
Henley, R.W. and Hughes, G.O. (2000) Underground fumaroles: “Excess heat” effects in vein formation. Economic Geology, 95, 453466.Google Scholar
Horton, J.D., San Juan, C.A. and Stoeser, D.B. (2017) The State Geologic Map Compilation (SGMC) Geodatabase of the Conterminous United States. United States Geological Survey data series, 1052, 46 pp.Google Scholar
Hughes, W. (1975) One theory on the formation of fire agate. Rocks & Minerals, 50, 4444.Google Scholar
Jones, B. (2012) Fire agate v. precious opal; two gems famous for their play of color. Rock & Gem, 42, 1214.Google Scholar
Kingma, K.J. and Hemley, R.J. (1994) Raman spectroscopic study of microcrystalline silica. American Mineralogist, 79, 269273.Google Scholar
Legodi, M.A. and de Waal, D. (2006) The preparation of magnetite, goethite, hematite and maghemite of pigment quality from mill scale iron waste. Dyes and Pigments, 74, 161168.CrossRefGoogle Scholar
McMackin, C.E. (1974) Fire agate – the rising star of the West. Rocks & Minerals, 49, 566568.CrossRefGoogle Scholar
Mohlenbrock, R.H. (2006) This Land: A Guide to Western National Forests. University of California Press, London, 422 pp.CrossRefGoogle Scholar
Moncada, D. (2008) Application of Fluid Inclusions and Mineral Textures in Exploration for Epithermal Precious Metals Deposits. The Virginia Polytechnic Institute, USA, 54 pp.Google Scholar
Moncada, D., Mutchler, S., Nieto, A., Reynolds, T.J., Rimstidt, J.D. and Bodnar, R.J. (2012) Mineral textures and fluid inclusion petrography of the epithermal Ag-Au deposits at Guanajuato, Mexico: Application to exploration. Journal of Geochemical Exploration, 114, 2035. Elsevier B.V.CrossRefGoogle Scholar
Moxon, T. (2017) A re-examination of water in agate and its bearing on the agate genesis enigma. Mineralogical Magazine, 81, 12231244.CrossRefGoogle Scholar
Moxon, T. and Carpenter, M.A. (2009) Crystallite growth kinetics in nanocrystalline quartz (agate and chalcedony). Mineralogical Magazine, 73, 551568.CrossRefGoogle Scholar
Moxon, T. and Ríos, S. (2004) Moganite and water content as a function of age in agate: an XRD and thermogravimetric study. European Journal of Mineralogy, 16, 269278.CrossRefGoogle Scholar
Murata, K.J. and Norman, M.B. (1976) An index of crystallinity for quartz. American Journal of Science, 276, 11201130.CrossRefGoogle Scholar
Newman, R. (2014) Exotic Gems. International Jewelry Publications Vol. 3, London, 136 pp.Google Scholar
Schumann, W. (2000) Gemstones of the World. Sterling, London, 272 pp.Google Scholar
Swamy, V., Muddle, B.C. and Dai, Q. (2006) Size-dependent modifications of the Raman spectrum of rutile TiO2. Applied Physics Letters, 89, 163118.CrossRefGoogle Scholar
Żaba, J. (2003) Ilustrowany Słownik Skał i Minerałów [Illustrated Dictionary of Minerals and Rocks]. Wydawnictwo Videograf II, Katowice, Poland, 503 pp. [in Polish].Google Scholar