VANDINI M. (a cura di), Riflessioni e Trasparenze. Diagnosi e conservazione di opere e manufatti vetrosi, Atti del Convegno A.I.Ar, Ravenna, 24-26 febbraio 2009, pp. 71-86, 2010
THE HISTORICAL METALLURGY SOCIETY 50th Anniversary Conference & AGM June 2013
London 14th-16th J... more THE HISTORICAL METALLURGY SOCIETY 50th Anniversary Conference & AGM June 2013
London 14th-16th June 2013
Abstract:
At the end of the second millennium BC the extractive metallurgy of copper in North-Eastern Italy achieved a peak of technological efficiency and mass production, as evidenced by the large number of metallurgical sites and the total amount of slags resulting from smelting activities. Though several smelting processes have been proposed, an agreed interpretation of the whole process is lacking.
Based on a collaboration with the Archaeological Heritage Office of the Autonomous Province of Trento and thanks to their recent excavations (directed by Dr. F. Nicolis and Dr. P. Bellintani, with the collaboration of E. Silvestri), over 70 slags from the Luserna, Transacqua and Segonzano sites (Trentino, Italy) have been characterized by means of OM, XRPD, XRF and SEM-EDS. A few metallurgical smelting experiments were carried out in order to explore both the slagging and the matting processes.
Three different types of archaeological slags have been distinguished from the mineralogical and chemical points of view: the two well-known Alpine LBA “coarse” and “flat” slag types, and a new intermediate type of slag here defined as “massive”. The three slag groups differ in the size and relative amount of the unreacted sulphides, the highly Cu-enriched matte, and the metallic copper. The ratio between the restitic quartz and the newly formed fayalite and magnetite is also a distinctive parameter, possibly related to the maximum temperature involved in each step.
It is proposed that the three types of slags are related to three distinct metallurgical steps: 1) the coarse slags are the product of the initial roasting/slagging operations, where a Cu-poor matte is produced, mainly of bornitic composition, 2) the massive slags are the result of the major matting process, where a Cu-rich matte (covellite-chalcocite composition) is produced, and 3) the thin flat slags are the product of the final refining process, formed directly at the surface of the raw molten metal.
39th International Symposium on Archaeometry: “50 years of ISA”
Leuven 28 May – 1 June 2012
Abst... more 39th International Symposium on Archaeometry: “50 years of ISA” Leuven 28 May – 1 June 2012
Abstract: The Recent and Late Bronze Age were periods of marked copper extraction activities in the Eastern Alps. Several furnaces and countless sites are known with abundant smelting slags of various type, including the Plattenschlake of well-defined composition and morphology (Anguilano et al. 2002, Weisgerber and Goldenberg 2004, Cierny 2008). The reconstruction of the Late Bronze Age smelting process are still debated, especially concerning the number and nature of the different high temperature working-steps employed in the process. The detailed investigation of the copper slags found in several Eastern Italian Alps LBA sites suggest that the smelting process was performed in at least three standardised steps related to different levels of copper extraction efficiency (Addis et al., 2011). To the purpose of verifying the working steps assumed on the basis of the analyses of the archaeometallurgical slags, two seasons of copper smelting experiments were performed in the Summer of 2010 and 2011. The first session of experiments principally aimed to explore the effect of different roasting cycles on the process. A number of twenty roasting experiments starting from three different types of commercial chalcopyrite were carried out using different strategies: charge roasting in crucibles heated in a furnace, and a open air roasting on piles of wood. X-Ray powder diffraction analyses on the starting materials and on the roasted products were performed at different stages during the process, which was repeated several times. These experiments allowed to select the most suitable charge to be used for subsequent smelting, to understand the efficiency of roasting strategies, and to assess the degree of transformation in the ores. Several smelting experiments were performed using a charge of roasted/unroasted chalcopyrite plus quartz, inserted in crucibles within a furnace heated by artificial air source and coal. The mineralogical associations and the copper enrichment of the matte obtained during the trasformations were measured. These analyses allowed stoichiometric optimization of the chalcopyrite/quartz ratio in the charge. The last experimental session was devoted to produce a highly copper-enriched matte from the optimized charge, and to understand the latter steps of the process including final copper extraction and formation of Plattenschlake-like slags. Based on the results of the experiments and in agreement with the observed features of the archaeological slags, a working 3-step process is proposed as the basic scheme for LBA copper extraction activity: (1) repeated roasting of the charge, (2) mass production of copper-enriched matte with formation of coarse and massive slags, (3) re-processing of the matte for the extraction of copper, with multiple production of flat slags.
ADDIS, A., ANGELINI, I., ARTIOLI, G.,2011. Final Bronze Age copper slags from Luserna (Trentino, Italy). Atti VII Congresso Nazionale di Archeometria, 2012, submitted.
ANGUILANO, L., ANGELINI, I., ARTIOLI, G., MORONI, M., BAUMGARTEN, B., OBERRAUCH, H., 2002. Smelting slags from Copper and Bronze Age archaeological sites in Trentino and Alto Adige. In: D’AMICO, C. (Eds.), Atti II Congresso Nazionale di Archeometria. Bologna 29 Gennaio-1 Febbraio 2002, Pàtron Editore, Bologna, 627-638.
CIERNY, J., 2008. Prähistorische Kupferproduktion in den südlichen Alpen – Region Trentino Orientale. Der Anschnitt, Beiheft 22, Bergbau-Museum, Bochum.
WEISGERBER, G., GOLDENBERG, G. 2004. Alpenkupfer – Rame delle Alpi. Der Anschnitt, Beiheft 17, Bergbau-Museu,m Bochum.
Traces of Complexity. Studi in Onore di Armando De Guio/ Studies in Honour of Armando De Guio, 2021
This contribution presents the first comprehensive survey of the protohistoric glasses found on t... more This contribution presents the first comprehensive survey of the protohistoric glasses found on the Altopiano dei Sette Comuni Vicentini in the sites of Monte Corgnon (Lusiana) and Bostel (Rotzo) during the excavations directed by Armando De Guio. Starting from the history of the studies, the work offers insights into the typo-chronology, stratigraphy, topography, and function of the finds considered. Also, the paper proposes and briefly discusses the preliminary results of the archaeometric analysis of the major, minor and trace elements carried out by LA-ICP-MS, as a means for understanding the raw materials, the coloring/ opacification technologies and the origin of the base glass.
A systematic and extensive analytical study was carried out on the loose inlays discovered in the... more A systematic and extensive analytical study was carried out on the loose inlays discovered in the Ptolemaic workshop of Tebtynis (Fayum oasis, Egypt). This paper presents data derived from the multi-methodological archaeometric investigations (optical microscopy, scanning electron microscopy-energy-dispersive spectroscopy, electron probe microanalysis, micro-Raman spectroscopy) performed on a set of intentionally colored and opacified glasses. In particular, we will discuss the textural, chemical, and mineralogical results related to the study of the yellow, yellowish-orange, red, and brown inlays and semi-finished/waste products now preserved at the Museo Egizio, Torino. The results highlight the presence of natron (low-magnesium glasses, LMG) and plant ash (high-magnesium glasses, HMG) base glass, coexisting with intermediate composition. Yellow samples are opacified using lead antimonates doped with iron and sometimes tin; conversely, yellowish-orange specimens and the only brown sample are characterized by nanocrystals of cuprite. Red glasses are found in two variants: Dull reds are HMG with colloidal metallic copper particles, while sealing-wax reds show LMG composition, associated with dendritic cuprite dispersed in a transparent, greenish matrix.
Inlays range among the most aesthetically pleasing and technically challenging glasses produced i... more Inlays range among the most aesthetically pleasing and technically challenging glasses produced in the Ptolemaic period. Despite the central role of this phase in the history of glass technology, little is known about the recipes and the technological knowledge of the Egyptian artisans. This paper will thus focus on the study of the materials from the secondary workshop of Tebtynis (Fayum oasis, Egypt). We report the first multi-methodological study comprising textural, chemical, and mineralogical analyses (OM, SEM-EDS, EPMA, and μ-Raman) on a set of 81 colorless, white, blue, and green samples carefully selected among the 800+ glasses from the craft area now stored at the Museo Egizio, Torino (Italy).
Our study offers the biggest compositional database of well-dated Ptolemaic glasses currently available in the literature, highlighting some interesting novelties regarding the silica and alkali sources, and the coloring and opacifying techniques employed. The results suggest a specialized craft of traditional origin, but open to innovation and experimentation, as expected from transitional phases.
An interesting assemblage of ancient ceramic materials connected or potentially connected with ga... more An interesting assemblage of ancient ceramic materials connected or potentially connected with gaming activities has been characterized from the archaeometric point of view. The materials (washer-like pieces, small spheres, and cubic dice, with and without inscriptions) were found in the Villa del Foro excavation (Alessandria, Italy). They are related to the early Ligurian population of the site and their frequent contacts with Etruscan both in Etruria and in the Po Valley, in a period spanning the early VI century BC till the first half of the V century BC. Starting from the materials evidence, hypotheses are proposed concerning their possible use and cultural meaning. The studied cubic dice are discussed in the wider context of the pre-Roman diffusion of these objects.
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London 14th-16th June 2013
Abstract:
At the end of the second millennium BC the extractive metallurgy of copper in North-Eastern Italy achieved a peak of technological efficiency and mass production, as evidenced by the large number of metallurgical sites and the total amount of slags resulting from smelting activities. Though several smelting processes have been proposed, an agreed interpretation of the whole process is lacking.
Based on a collaboration with the Archaeological Heritage Office of the Autonomous Province of Trento and thanks to their recent excavations (directed by Dr. F. Nicolis and Dr. P. Bellintani, with the collaboration of E. Silvestri), over 70 slags from the Luserna, Transacqua and Segonzano sites (Trentino, Italy) have been characterized by means of OM, XRPD, XRF and SEM-EDS. A few metallurgical smelting experiments were carried out in order to explore both the slagging and the matting processes.
Three different types of archaeological slags have been distinguished from the mineralogical and chemical points of view: the two well-known Alpine LBA “coarse” and “flat” slag types, and a new intermediate type of slag here defined as “massive”. The three slag groups differ in the size and relative amount of the unreacted sulphides, the highly Cu-enriched matte, and the metallic copper. The ratio between the restitic quartz and the newly formed fayalite and magnetite is also a distinctive parameter, possibly related to the maximum temperature involved in each step.
It is proposed that the three types of slags are related to three distinct metallurgical steps: 1) the coarse slags are the product of the initial roasting/slagging operations, where a Cu-poor matte is produced, mainly of bornitic composition, 2) the massive slags are the result of the major matting process, where a Cu-rich matte (covellite-chalcocite composition) is produced, and 3) the thin flat slags are the product of the final refining process, formed directly at the surface of the raw molten metal.
Leuven 28 May – 1 June 2012
Abstract: The Recent and Late Bronze Age were periods of marked copper extraction activities in the Eastern Alps. Several furnaces and countless sites are known with abundant smelting slags of various type, including the Plattenschlake of well-defined composition and morphology (Anguilano et al. 2002, Weisgerber and Goldenberg 2004, Cierny 2008). The reconstruction of the Late Bronze Age smelting process are still debated, especially concerning the number and nature of the different high temperature working-steps employed in the process.
The detailed investigation of the copper slags found in several Eastern Italian Alps LBA sites suggest that the smelting process was performed in at least three standardised steps related to different levels of copper extraction efficiency (Addis et al., 2011). To the purpose of verifying the working steps assumed on the basis of the analyses of the archaeometallurgical slags, two seasons of copper smelting experiments were performed in the Summer of 2010 and 2011.
The first session of experiments principally aimed to explore the effect of different roasting cycles on the process. A number of twenty roasting experiments starting from three different types of commercial chalcopyrite were carried out using different strategies: charge roasting in crucibles heated in a furnace, and a open air roasting on piles of wood. X-Ray powder diffraction analyses on the starting materials and on the roasted products were performed at different stages during the process, which was repeated several times. These experiments allowed to select the most suitable charge to be used for subsequent smelting, to understand the efficiency of roasting strategies, and to assess the degree of transformation in the ores.
Several smelting experiments were performed using a charge of roasted/unroasted chalcopyrite plus quartz, inserted in crucibles within a furnace heated by artificial air source and coal. The mineralogical associations and the copper enrichment of the matte obtained during the trasformations were measured. These analyses allowed stoichiometric optimization of the chalcopyrite/quartz ratio in the charge.
The last experimental session was devoted to produce a highly copper-enriched matte from the optimized charge, and to understand the latter steps of the process including final copper extraction and formation of Plattenschlake-like slags.
Based on the results of the experiments and in agreement with the observed features of the archaeological slags, a working 3-step process is proposed as the basic scheme for LBA copper extraction activity: (1) repeated roasting of the charge, (2) mass production of copper-enriched matte with formation of coarse and massive slags, (3) re-processing of the matte for the extraction of copper, with multiple production of flat slags.
ADDIS, A., ANGELINI, I., ARTIOLI, G.,2011. Final Bronze Age copper slags from Luserna (Trentino, Italy). Atti VII Congresso Nazionale di Archeometria, 2012, submitted.
ANGUILANO, L., ANGELINI, I., ARTIOLI, G., MORONI, M., BAUMGARTEN, B., OBERRAUCH, H., 2002. Smelting slags from Copper and Bronze Age archaeological sites in Trentino and Alto Adige. In: D’AMICO, C. (Eds.), Atti II Congresso Nazionale di Archeometria. Bologna 29 Gennaio-1 Febbraio 2002, Pàtron Editore, Bologna, 627-638.
CIERNY, J., 2008. Prähistorische Kupferproduktion in den südlichen Alpen – Region Trentino Orientale. Der Anschnitt, Beiheft 22, Bergbau-Museum, Bochum.
WEISGERBER, G., GOLDENBERG, G. 2004. Alpenkupfer – Rame delle Alpi. Der Anschnitt, Beiheft 17, Bergbau-Museu,m Bochum.
Our study offers the biggest compositional database of well-dated Ptolemaic glasses currently available in the literature, highlighting some interesting novelties regarding the silica and alkali sources, and the coloring and opacifying techniques employed. The results suggest a specialized craft of traditional origin, but open to innovation and experimentation, as expected from transitional phases.