 | Hartmann, Léo Afraneo, da Cunha Duarte, Lauren, Massonne, Hans-Joachim, Michelin, Cassiana, Rosenstengel, Leonardo Manara, Bergmann, Magda, Theye, Thomas, Pertille, Juliana, Arena, Karine Rosa, Duarte, Sandro Kucera, Pinto, Viter Magalhães, Barboza, Eduardo Guimarães, Rosa, Maria Luiza C.C., Wildner, Wilson (2012) Sequential opening and filling of cavities forming vesicles, amygdales and giant amethyst geodes in lavas from the southern Paraná volcanic province, Brazil and Uruguay. International Geology Review, 54 (1) 1-14 doi:10.1080/00206814.2010.496253 | Journal (article/letter/editorial) | | southern Paraná volcanic province, Brazil and Uruguay a b c Léo Afraneo Hartmann , Lauren da Cunha...southern Paraná volcanic province, Brazil and Uruguay, International Geology Review, 54:1, 1-14, DOI:...southern Paraná volcanic province, Brazil and Uruguay Léo Afraneo Hartmanna *, Lauren da Cunha Duarteb...the world and has large deposits of amethyst and agate (calcite, gypsum) geodes. Specimen-quality minerals...South America, not only in Brazil but also in Uruguay, Argentina, and Paraguay (Bellieni et al. 1984) |  | Duarte, Lauren C., Hartmann, Leo A., Ronchi, Luiz H., Berner, Zsolt, Theye, Thomas, Massonne, Hans J. (2011) Stable isotope and mineralogical investigation of the genesis of amethyst geodes in the Los Catalanes gemological district, Uruguay, southernmost Paraná volcanic province. Mineralium Deposita, 46 (3) 239-255 doi:10.1007/s00126-010-0323-6 | Journal (article/letter/editorial) | | genesis of amethyst geodes in the Los Catalanes gemological district, Uruguay, southernmost Paraná volcanic...amethyst-geode deposits of the Los Catalanes gemological district, Uruguay, constrain processes operative...amethyst and agate geodes (600 tons/month) are Brazil (Ametista do Sul) and Uruguay (Los Catalanes). The cylindrical...the Serra Geral Group, giant amethyst geodes and agate geodes occur in volcanic rocks that cover a large...Gramado-type basaltic lavas (e.g., Los Catalanes gemological district, andesite and basaltic andesite—Duarte |  | Hartmann, L.A., Medeiros, J.T.N., Baggio, S.B., Antunes, L.M. (2015) Controls on prolate and oblate geode geometries in the Veia Alta basalt flow, largest world producer of amethyst, Paraná volcanic province, Brazil. Ore Geology Reviews, 66. 243-251 doi:10.1016/j.oregeorev.2014.11.005 | Journal (article/letter/editorial) | | geodes produced in the mines of the Ametista do Sul district are 4 m tall and 1 m in diameter at the base,...The world's largest production of amethyst and agate geodes comes from mines in the Paraná volcanic province...amethyst mining district in Brazil, followed by the Los Catalanes gemological district in Uruguay. The volcanic...volcanic province covers 915,000 km2 in Brazil, Uruguay, Argentina and Paraguay, is underlain by the strong...Rio Grande do Sul. In the Ametista do Sul mining district, there is a sequence of 1000 m of basalt and some |  | Gilg, H. Albert, Krüger, Yves, Taubald, Heinrich, van den Kerkhof, Alfons M., Frenz, Martin, Morteani, Giulio (2014) Mineralisation of amethyst-bearing geodes in Ametista do Sul (Brazil) from low-temperature sedimentary brines: evidence from monophase liquid inclusions and stable isotopes. Mineralium Deposita, 49 (7) 861-877 doi:10.1007/s00126-014-0522-7 | Journal (article/letter/editorial) | | Province in southern Brazil (Ametista do Sul) and Uruguay (Artigas), i.e. in rocks with low silica and radioactive...Sul, Brazil, and Artigas or sometimes named “Los Catalanes gem field”, northern Uruguay. They are located...2003; Rosenstengel and Hartmann 2012), while in Artigas the amethyst geodes are hosted in Ti-poor Gramado-type...districts of Ametista do Sul, Brazil, and Artigas, Uruguay (from Gilg et al. 2003) a specific level...partly banded microcrystalline quartz (chalcedony or agate). Sulphides are locally found in stage I and have |  | | Journal (article/letter/editorial) | | W ord to the Wise Geode JOHN RAKOVAN Department of Geology and Environmental Sciences Miami University...(volcanic) geode, with a thicker chalcedony rind (agate) than seen in figure 2, lined with smoky quartz...two balls of okenite (not a geode) from the Pune district, Maharashtra, India. The rounded shape of the...(fig. 3), which are common in Mexico, Brazil, Uruguay, and other countries, are essentially large amygdules...amethystbearing geodes from Los Catalanes Gemological district, Artigas, Uruguay, southern Paraná Magmatic |  | Baggio, S.B., Hartmann, L.A., Andrade, R.H.P., Rizzotto, G.J., Duarte, S.K., Knijnik, D.B., Simões-Neto, J.A. (2015) Basalt stratigraphy and silica gossans in Campo Grande and Serra de Maracaju, Mato Grosso do Sul, Paraná Volcanic Province. Ore Geology Reviews, 69. 73-87 doi:10.1016/j.oregeorev.2015.01.015 | Journal (article/letter/editorial) | | indicating the presence of calcite, amethyst and agate geode deposits along with native copper mineralization...readily locate favorable areas for MA amethyst and agate geode deposits and native copper mineralization...of 917,000 km2 (Frank et al., 2009) in Brazil, Uruguay, Argentina and Paraguay (Fig.1) with a lava volume...The world´s MA largest deposits of amethyst and agate are hosted in rocks from the two magma types. The...concentrated in Ametista do Sul in Brazil and Los D Catalanes in Uruguay (Juchem et al., 2010; Silva, 2010). |  | Arena, K.R., Hartmann, L.A., Baggio, S.B. (2014) Geological controls of copper, gold and silver in the Serra Geral Group, Realeza region, Paraná, Brazil. Ore Geology Reviews, 63. 178-200 doi:10.1016/j.oregeorev.2014.05.005 | Journal (article/letter/editorial) | | and are well known as host rocks of amethyst and agate mineralization and occurrences of native copper...Geral Group is the host of world class amethyst and agate deposits and may also contain large deposits of...their filling with amethyst and agate. The main deposits of amethyst and agate (Duarte et al., 2009; Hartmann...LeHuray, 1989) is comparable to the Vista Alegre district (Pinto et al., 2011a) in the Paraná volcanic province...Genesis of native copper lodes in the Keweenaw District, northern RI P T Michigan: A hybrid evolved |  | | Journal (article/letter/editorial) | | 119017, Russia ABSTRACT Practically all aspects of agate genesis generate debate. The time is ripe to clarify...the related famous amethyst geodes of Brazil and Uruguay. Agates form over a wide range of temperatures...overlapping fresh flows upon the cooling older agate-bearing lava flow. In a submarine setting, phase...rocks and the famous amethyst druses of Brazil and Uruguay formed at the moderate temperatures associated...and onyx banding. Keywords: vesicles, amygdules, agate texture, microglobulae, volcanism, colloids, silica |  | | Journal (article/letter/editorial) | | acidic volcanic host rocks. Samples from the main agate occurrences of Chemnitz, Hohenstein-Ernstthal, St...detailed analyses. The results of the study show that agate formation can be related to volcanic activity (Rochlitz...which formed during cooling of welded ignimbrite. Agate formation temperatures of probably >150°C were calculated...rocks and point to fractionation processes during agate formation. The specific geochemical features indicate...___________________________________ Keywords: Agate, Quartz, Permian volcanics, Saxony, Trace elements |  | | Journal (article/letter/editorial) | | Review Mineralogy, Geochemistry and Genesis of Agate—A Review Jens Götze 1, *, Robert Möckel 2 and Yuanming...40, 09599 Freiberg, Germany; r.moeckel@hzdr.de Department of Geological Sciences, University of Saskatchewan...20 November 2020 Abstract: Agate—a spectacular form of SiO2 and a famous gemstone—is...interstitial molecular H2 O and silanol groups. Most agate occurrences worldwide are related to SiO2 -rich...rocks. It is assumed that the supply of silica for agate formation is often associated with late- or post-volcanic |  | | Book | | Yuanming Pan Mineralogy, Geochemistry and Genesis of Agate—A Review Reprinted from: Minerals 2020, 10, 1037.... . . . . 5 Terry Moxon and Galina Palyanova Agate Genesis: A Continuing Enigma Reprinted from: Minerals...Lei Ji and Xuemei He Gemological Characteristics and Origin of the Zhanguohong Agate from Beipiao, Liaoning...Sciences. She is currently a lecturer at the Department of Mineralogy and Geochemistry of Novosibirsk...source of the silica required for the growth of agate remains largely unknown. The first known descriptive |  | | Book | | Macrocrystalline and Microcrystalline Quartz in Agate Using Thermogravimetry-Mass-Spectrometry Reprinted...modifications and varieties (e.g., opal, chalcedony, agate, quartz, amethyst). Following the fundamental idea...Macrocrystalline and Microcrystalline Quartz in Agate Using Thermogravimetry-Mass-Spectrometry. Minerals...Freiberg, Brennhausgasse 14, 09596 Freiberg, Germany Department of Geological Sciences, University of Saskatchewan...milled to a grain size of <30 μm using a pre-cleaned agate mortar. The powdered sample was digested in a glassy |  | | Book | | Macrocrystalline and Microcrystalline Quartz in Agate Using Thermogravimetry-Mass-Spectrometry Reprinted...modifications and varieties (e.g., opal, chalcedony, agate, quartz, amethyst). Following the fundamental idea...Macrocrystalline and Microcrystalline Quartz in Agate Using Thermogravimetry-Mass-Spectrometry. Minerals...Freiberg, Brennhausgasse 14, 09596 Freiberg, Germany Department of Geological Sciences, University of Saskatchewan...milled to a grain size of <30 μm using a pre-cleaned agate mortar. The powdered sample was digested in a glassy |
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