The Analysis of 18th Century Glass Trade Beadsfrom Fort Niagara: Insight into CompositionalVariation and Manufacturing Techniques

An assemblage of 445 archaeological glass trade beads excavated from Old Fort Niagara, Youngstown, New York in 2007 were analyzed to determine their manufacturing technology and elemental composition. Analytical techniques included reflected light microscopy, handheld X-ray fluorescence (XRF), and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS). Optical microscopy revealed the manufacturing technology of the beads and uncovered discrepancies between the current method of visual identification for bead type and color and the structures and colors revealed through scientific analysis. Elemental analysis revealed a new turquoise blue bead composition

Microscopic observations to track the behaviour of cyclododecane crystallisation and the effect of crystal formation on fragile porous substrates

This paper is published in the book ‘Subliming Surfaces: Volatile Binding Media in Heritage Conservation’, ed. Christina Rozeik (University of Cambridge Museums, 2018), pp. 67-78.The objective of this project is to observe the formation and changing structure of CDD crystals and their effect on painted porous surfaces. To investigate the interaction of CDD with absorbent and weak substrates, mock-ups of fragile painted plaster were prepared and CDD was applied to each of the mock-ups as either a hot melt or dissolved in Stoddard solvent. Time-lapse microphotography recorded the behaviour of the CDD crystals regularly over a span of six weeks. Scanning electron microscopy and confocal microscopy were utilised before application and after sublimation of CDD to characterise the surface morphology and porosity of the substrate, and to observe any damage that the CDD crystals may have caused to the surface of the artefact. Three computations were used in conjuction with confocal microscopy in order to analyse the topographic deviations caused by CDD interaction: surface subtraction, profile extraction, and horizontal contour extraction. It was concluded that CDD may be altering the original surface of the samples by widening pre-existing cracks, altering particle morphology, and inducing minor elevation changes in the overall topography. However, it does not impart a new texture to the plaster nor does it appear to cause new or original cracks in the substrate

Archaeological block-lifting with volatile binding media: exploring alternatives to cyclododecane

This paper is published in the book ‘Subliming Surfaces: Volatile Binding Media in Heritage Conservation’, ed. Christina Rozeik (University of Cambridge Museums, 2018), pp. 97-99.Cyclododecane (CDD) is the only volatile solid currently in common use in archaeology, usually as a consolidant in the practice of block-lifting. CDD is considered by many to be an advantageous consolidant in block-lifting due to the fact that it can be removed from the block through sublimation, whereas traditional adhesive consolidants must be removed (and then only partially) through the use of solvents and mechanical action, which can be hard on the artefacts. CDD’s main drawback is its sublimation rate, which is slow enough that subsequent treatment of heavily coated objects cannot always be completed within a suitable time frame. This research compares CDD with a range of alternative volatile binding media to determine their relative usefulness for block-lifting. Camphene was determined to be unsuitable for archaeological block-lifting due to its lack of rigidity, excessively fast sublimation rate and typical impurity. Menthol was found to have the desired properties but was susceptible to melting in a warm climate, as observed in a field test. Its melting temperature may be ideal in colder conditions. Mixtures of CDD and menthol with a low menthol content were found to have the desired properties but require further testing

Maya Metallurgical Technology in Late Postclassic-Spanish Colonial Times: The View from Lamanai, Belize

Recent archaeometallurgical studies at the ancient Maya site of Lamanai, Belize have begun to reveal the nature of copper metallurgy in the centuries just prior to and during Spanish contact in the Southern Maya Lowland Area. More copper artifacts have been recovered from controlled archaeological excavations at Lamanai than at any other site in the Southern Maya Lowland area. A total of 187 copper objects dating to the 12th through 16th centuries AD have been recovered; among these objects are ingots or pigs, blanks, prills and a substantial number of mis-cast objects, many of which are bells. The archaeological contexts in which copper bells, axes, needles, fish hooks, rings, and clothing ornaments have been recovered will be summarised. Forming technologies used in the creation of Maya copper artifacts as well as their chemical compositions were studied using scanning electron microscopy and optical light microscopy. The results of chemical compositional and microstructural analyses will be presented and discussed in the contexts of larger social and economic spheres that were part of the Maya world just before and during Spanish contact in Belize.De récentes études concernant l’archéométallurgie sur l’ancien site maya de Lamanai, Belize ont permis de révéler la nature de la métallurgie du cuivre des siècles avant et pendant la période de contact espagnol dans la zone sud des basses terres mayas. Le nombre d’artéfacts en cuivre découverts lors de fouilles archéologiques contrôlées à Lamanai dépasse tout ce qui a été mis au jour dans les autres sites localisés dans la même région. Un total de 187 objets en cuivre datant des xiie jusqu’au xvie siècle de notre ère ont été découverts. Parmi ces objets on retrouve entre autres des lingots ou barres en cuivre, des douilles, sphérules ainsi qu’un certain nombre d’objets mal moulés, lesquels sont principalement des cloches. Les contextes archéologiques dans lesquels les cloches en cuivre, haches, aiguilles, hameçons, anneaux ainsi que les ornements pour vêtements ont été découverts seront brièvement expliqués. Les moyens technologiques utilisés dans la création d’artéfacts mayas en cuivre tout comme leurs compositions chimiques ont été étudiés par microscope électronique à balayage ainsi que microscope optique. Les résultats des composants chimiques et analyses microstructurales seront présentés et expliqués dans les contextes plus larges des sphères sociales et économiques qui faisaient partie intégrantes du monde maya avant et pendant les contacts espagnols au Belize

Obtaining cross-sections of paint layers in cultural artifacts using femtosecond pulsed lasers

Recently, ultrafast lasers exhibiting high peak powers and extremely short pulse durations have created a new paradigm in materials processing. The precision and minimal thermal damage provided by ultrafast lasers in the machining of metals and dielectrics also suggests a novel application in obtaining precise cross-sections of fragile, combustible paint layers in artwork and cultural heritage property. Cross-sections of paint and other decorative layers on artwork provide critical information into its history and authenticity. However, the current methodology which uses a scalpel to obtain a cross-section can cause further damage, including crumbling, delamination, and paint compression. Here, we demonstrate the ability to make controlled cross-sections of paint layers with a femtosecond pulsed laser, with minimal damage to the surrounding artwork. The femtosecond laser cutting overcomes challenges such as fragile paint disintegrating under scalpel pressure, or oxidation by the continuous-wave (CW) laser. Variations in laser power and translational speed of the laser while cutting exhibit different benefits for cross-section sampling. The use of femtosecond lasers in studying artwork also presents new possibilities in analyzing, sampling, and cleaning of artwork with minimal destructive effects

Panel 5: Shaping Identity: Re-examining Gender and Politics

PANEL 5 of the 2013 Graduate History Conference features presentations and papers under the topic of Shaping Identity: Re-examining Gender and Politics. Additional information about these presentations: History and Archaeology in Women’s Clothing of Late Antiquity: 450-600 C.E. Heather Bump (M.A. in History) The Pains of Allegory: Tracing Trauma in Courtly Elizabethan Discourse Alexander McAdams (M.A. in English) \u27Satisfying Pagan Thirst for Beauty Unadorned\u27: Representations of Transgressive Sexuality in FIRE!! Andrew Lester (M.A. in American Studies) John James Audubon and the Naturalization of the Native American Miles Shugar (M.A. in Historical Archaeology) Chair: Kathy Shinnick Commentator: Aaron Lecklider, Assistant Professor of American Studie

The Copper CHARM Set: A New Set of Certified Reference Materials for the Standardization of Quantitative X-Ray Fluorescence Analysis of Heritage Copper Alloys

International audienceThis paper introduces a new set of certified reference materials designed to aid scientists and conservators working in cultural heritage fields with quantitative X-ray fluorescence analysis of historical and prehistoric copper alloys. This set has been designated as the Copper CHARM Set (Cultural Heritage Alloy Reference Material Set). The Copper CHARM Set is designed to be used by a wide range of museum-, art- and archaeology-oriented scientists and conservators to help improve the accuracy and range of their calibrations for quantitative ED–XRF spectrometry of copper alloys, and also increase the number of elements that can routinely be quantified. In addition, the common use of a single core set of the reference materials is designed to significantly improve inter-laboratory reproducibility, allowing greater data sharing between researchers and thus furthering possibilities for collaborative study