Non-Destructive High-Resolution X-ray Diffraction for Cultural Heritage
Lead Research Organisation:
University of Leicester
Department Name: Space Research Centre
Abstract
Many different analytical techniques are commonly applied in the scientific analysis of heritage objects in order to elucidate their material properties. Each technique has advantages and disadvantages in terms of the type of information returned, complexity and expense, sample preparation requirements and applicability to different types of material objects. While X-ray fluorescence (XRF) is very useful in providing elemental information, and techniques such as Fourier-transform infrared spectroscopy and Raman spectroscopy can yield phase information, only X-ray diffraction (XRD) allows the definitive and unambiguous identification of crystallographic phases. Despite this, the use of XRD in archaeometry has been relatively sporadic and of utility only in niche areas, largely because of sample preparation requirements. This project aims to bring exciting advances in non-destructive XRD techniques to the archaeometric analysis of cultural heritage and archaeological artefacts. The innovative XRD methods developed by the applicants enable high resolution XRD analysis of objects with no sample preparation requirement at all. While twenty years ago sampling of artefacts was considered standard practice, the growth of non-destructive techniques such as handheld XRF have made curators at museums and other collections very much less willing to allow invasive procedures. Maintaining the physical integrity of heritage artefacts is now considered to be of paramount importance.
There are certain classes of heritage objects for which destructive sampling is currently the only realistic approach to determining provenance. Stone artefacts are a primary example. Many stone objects in Western Museums are from the art market and doubts have been expressed about the authenticity of many. The most effective method of provenancing stone artefacts is the detailed characterisation of the mineralogical composition in order to identify the geological source, but destructive sampling is nearly always currently required for this purpose. A second major application area is the identification of pigments in fine art paintings and on painted objects such as mummy portraits and Indian miniatures. Although Raman spectroscopy can successfully identify a significant proportion of pigments, there remain an important number for which the method is ineffective. Pigments have unique diffraction pattern fingerprints and XRD studies can provide the critical information for essentially all pigments. The study of stone artefacts and of paintings and painted artefacts will form a major focus of the proposed project.
Currently, this innovative XRD technique requires synchrotron facilities for implementation. The applicants will demonstrate the method using cutting-edge high-resolution X-ray detectors (superconducting transition-edge sensor arrays) at the National Institute of Standards and Technology in the US in proof-of-principle experiments. This work will support the eventual transition of the technique away from synchrotrons and into the laboratory and museum. An additional aim is to investigate the archaeometric capability of a prototype handheld XRD instrument, based on the same underlying technique but having much lower resolution. Previous work with this prototype device strongly suggests that the analysis of metallic heritage objects is an especially promising area.
The avoidance of the need to extract samples from high-value and rare objects is a highly-significant advantage and is applicable in other research areas. These include palaeontology and the study of meteorites and planetary materials brought to Earth by sample-return missions.
There are certain classes of heritage objects for which destructive sampling is currently the only realistic approach to determining provenance. Stone artefacts are a primary example. Many stone objects in Western Museums are from the art market and doubts have been expressed about the authenticity of many. The most effective method of provenancing stone artefacts is the detailed characterisation of the mineralogical composition in order to identify the geological source, but destructive sampling is nearly always currently required for this purpose. A second major application area is the identification of pigments in fine art paintings and on painted objects such as mummy portraits and Indian miniatures. Although Raman spectroscopy can successfully identify a significant proportion of pigments, there remain an important number for which the method is ineffective. Pigments have unique diffraction pattern fingerprints and XRD studies can provide the critical information for essentially all pigments. The study of stone artefacts and of paintings and painted artefacts will form a major focus of the proposed project.
Currently, this innovative XRD technique requires synchrotron facilities for implementation. The applicants will demonstrate the method using cutting-edge high-resolution X-ray detectors (superconducting transition-edge sensor arrays) at the National Institute of Standards and Technology in the US in proof-of-principle experiments. This work will support the eventual transition of the technique away from synchrotrons and into the laboratory and museum. An additional aim is to investigate the archaeometric capability of a prototype handheld XRD instrument, based on the same underlying technique but having much lower resolution. Previous work with this prototype device strongly suggests that the analysis of metallic heritage objects is an especially promising area.
The avoidance of the need to extract samples from high-value and rare objects is a highly-significant advantage and is applicable in other research areas. These include palaeontology and the study of meteorites and planetary materials brought to Earth by sample-return missions.
Planned Impact
The uniqueness of this research lies in the ability to perform highly accurate crystallographic analysis without the need for any preparation of the sample, even for markedly non-planar and textured objects. This capability is greatly enabling, opening up new opportunities for detailed investigations of the crystallographic material properties of a wide range of objects.
Museums and their curators will benefit from access to the new knowledge generated during the project and, in the longer term, through the establishment of highly capable XRD analytical facilities situated within larger museums with more extensive collections. The new knowledge will lead to improved explanatory and contextual information displays about collections. Access to up-to-date research will support museums as evolving entities within communities, contributing to individual and societal well-being and supporting economic tourism and so benefiting the wider public.
There is potential for further significant economic impact through verification of the authenticity of artworks, directly benefiting auction houses and insurance companies. For example, the identification of pigments can place strong constraints on the date and location of manufacture and this information is extremely valuable for high-worth artworks. Buyers of art, including museums, will benefit through assurance of the veracity of their purchases. The UK is home to several internationally-leading auction houses (Christies, Sothebys, Bonhams) and the proposed research will support these leading roles, ultimately to the benefit of the UK economy.
The PDRA employed on the project will receive first-class cross-disciplinary scientific training at the Universities of Leicester and Cranfield. S/he will develop key employability skills, including communication, presentation and organisational skills and team working. Summer students will also be employed on the project and will have the opportunity to gain an invaluable insight into cutting-edge research, guiding their decisions about future careers.
Museums and their curators will benefit from access to the new knowledge generated during the project and, in the longer term, through the establishment of highly capable XRD analytical facilities situated within larger museums with more extensive collections. The new knowledge will lead to improved explanatory and contextual information displays about collections. Access to up-to-date research will support museums as evolving entities within communities, contributing to individual and societal well-being and supporting economic tourism and so benefiting the wider public.
There is potential for further significant economic impact through verification of the authenticity of artworks, directly benefiting auction houses and insurance companies. For example, the identification of pigments can place strong constraints on the date and location of manufacture and this information is extremely valuable for high-worth artworks. Buyers of art, including museums, will benefit through assurance of the veracity of their purchases. The UK is home to several internationally-leading auction houses (Christies, Sothebys, Bonhams) and the proposed research will support these leading roles, ultimately to the benefit of the UK economy.
The PDRA employed on the project will receive first-class cross-disciplinary scientific training at the Universities of Leicester and Cranfield. S/he will develop key employability skills, including communication, presentation and organisational skills and team working. Summer students will also be employed on the project and will have the opportunity to gain an invaluable insight into cutting-edge research, guiding their decisions about future careers.
Organisations
- University of Leicester (Lead Research Organisation)
- Natural Environment Research Council (Co-funder)
- Courtauld Institute of Art (University of London) (Collaboration)
- University College London (Collaboration)
- Nottingham Trent University (Collaboration)
- Mary Rose Trust (Collaboration)
- National Institute of Standards & Technology (NIST) (Collaboration)
- British Museum (Collaboration)
- CRANFIELD UNIVERSITY (Collaboration)
- University of Leuven (Collaboration)
- National Institute of Standards and Technology (Project Partner)
- Art Analysis & Research Inc. (Project Partner)
Publications
Hiley C
(2022)
High-resolution non-invasive X-ray diffraction analysis of artists' paints
in Journal of Cultural Heritage
Description | The overarching purpose of this research project was the application of a unique X-ray diffraction (XRD) methodology which is almost completely impervious to the morphology of the sample, in contrast to conventional XRD methods. When implemented at high resolution at the Diamond Light Source synchrotron, the technique returns very high quality diffraction data, entirely non-invasively; this combination of characteristics represents the holy grail within cultural heritage materials research. A series of visits to Diamond were made in order to validate the technique for a wide range of heritage artefact types, including paintings, high-value Chinese porcelain, wall painting fragments, and stone and rock objects such as Roman white marble. The technique was shown to be effective in the material analysis of heritage objects and detailed knowhow was developed in how to optimise the measurements. |
Exploitation Route | The PI plans to establish an advanced laboratory facility based on a TES array spectrometer that can be accessed by a range of users, including industrial partners in aerospace, for example.. This facility would also be transportable to enable in situ field campaigns at museums and art institutes, enabling transformative research in the field of cultural heritage. An application to the EPSRC strategic equipment fund was rejected on the grounds that the applications lie substantially outside the EPSRC's remit. The PI plans to submit a proposal to the new UKRI cross-council scheme for funding interdisciplinary research. |
Sectors | Aerospace Defence and Marine Manufacturing including Industrial Biotechology Culture Heritage Museums and Collections |
Description | The overarching purpose of this research project was the application of a unique X-ray diffraction (XRD) methodology which is almost completely impervious to the morphology of the sample, in contrast to conventional XRD methods. When implemented at high resolution at the Diamond Light Source synchrotron, the technique returns very high quality diffraction data, entirely non-invasively; this combination of characteristics represents the holy grail within cultural heritage materials research. A series of visits to Diamond were made in order to validate the technique for a wide range of heritage artefact types, including paintings, high-value Chinese porcelain, wall painting fragments, and stone and rock objects such as Roman white marble. The technique was shown to be effective in the material analysis of heritage objects and detailed knowhow was developed in how to optimise the measurements. The PI plans to establish an advanced laboratory facility based on a TES array spectrometer that can be accessed by a range of users, including industrial partners in aerospace, for example. This facility would also be transportable to enable in situ field campaigns at museums and art institutes, enabling transformative research in the field of cultural heritage. There appears to be a good fit with the AHRC's RICHeS programme and the PI will submit an application to a forthcoming call within this programme, though it is not expected until late 2025. |
First Year Of Impact | 2022 |
Sector | Aerospace, Defence and Marine,Culture, Heritage, Museums and Collections |
Impact Types | Cultural |
Description | DEVELOPING IN SITU RESOURCE UTILISATION PRODUCTION TECHNOLOGY 2 (DISRUPT-2). |
Amount | £168,807 (GBP) |
Funding ID | UKSAG22_0046G |
Organisation | UK Space Agency |
Sector | Public |
Country | United Kingdom |
Start | 12/2022 |
End | 12/2024 |
Description | Digital Imaging X-ray Source - Proving the Fast Response |
Amount | £30,860 (GBP) |
Organisation | University of Leicester |
Sector | Academic/University |
Country | United Kingdom |
Start | 09/2023 |
End | 03/2024 |
Description | Knowledge Exchange, Impact & Proof of Concept Development Fund Application |
Amount | £13,127 (GBP) |
Organisation | University of Leicester |
Sector | Academic/University |
Country | United Kingdom |
Start | 04/2022 |
End | 07/2022 |
Description | Proof of Concept Fund 2019-20 Call 8 |
Amount | £5,000 (GBP) |
Organisation | University of Leicester |
Sector | Academic/University |
Country | United Kingdom |
Start | 02/2020 |
End | 06/2020 |
Description | Research Equipment and Infrastructure Fund - Stand Alone call 2018/19 |
Amount | £39,428 (GBP) |
Organisation | University of Leicester |
Sector | Academic/University |
Country | United Kingdom |
Start | 03/2019 |
End | 07/2019 |
Title | Crystalline Phase Quantification with Energy-Dispersive XRD Data using Rietveld Analysis |
Description | The quantification of crystalline phases in a mixture is relatively unusual in energy-dispersive XRD because of the difficulty in accounting for the variation in the relevant parameters with X-ray energy, amongst other reasons. We have developed methods which can overcome this problem either by segmenting the data into relatively short ranges over which variation of parameters is small, or by applying an overall scaling function (with a small number of fitted parameters) to account for the variations. |
Type Of Material | Data analysis technique |
Year Produced | 2019 |
Provided To Others? | No |
Impact | This method is having significant impact within our own research, enabling the relative quantification of the crystalline phases in artistic paints, for example. We plan to publish this method in 2020. |
Description | Analysis of wall paintings/fragments with the Courtauld |
Organisation | Courtauld Institute of Art (University of London) |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | Application of a non-invasive but high resolution XRD technique at the Diamond synchrotron, including data acquisition and processing, and crystallographic interpretation. |
Collaborator Contribution | Provision of wall painting fragments from the Courtauld archive and expert interpretation of the analytical results from an art historical perspective. |
Impact | No outcomes as yet. Highly multidisciplinary: X-ray physics, materials analysis by XRD and XRF (crystallographic and elemental analyses), and art historical interpretation. |
Start Year | 2018 |
Description | Analysis of wall paintings/fragments with the Courtauld |
Organisation | Nottingham Trent University |
Department | School of Science and Technology |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | Application of a non-invasive but high resolution XRD technique at the Diamond synchrotron, including data acquisition and processing, and crystallographic interpretation. |
Collaborator Contribution | Provision of wall painting fragments from the Courtauld archive and expert interpretation of the analytical results from an art historical perspective. |
Impact | No outcomes as yet. Highly multidisciplinary: X-ray physics, materials analysis by XRD and XRF (crystallographic and elemental analyses), and art historical interpretation. |
Start Year | 2018 |
Description | Collaboration with NIST in order to test the efficacy of TES array detectors for high-resolution back-reflection EDXRD |
Organisation | National Institute of Standards & Technology (NIST) |
Department | Quantum Sensors Group |
Country | United States |
Sector | Public |
PI Contribution | The collaboration centres on a short experimental campaign on the application of NIST superconducting transition-edge sensor arrays in non-destructive XRD analysis of cultural heritage objects. The campaign was originally expected to take place in late 2020 but the pandemic delayed these plans because it involved travel of staff from the UK to the USA. Instead, NIST has put together a vacuum chamber for testing and a set of samples have been sent to NIST. The experiments have been completed and analysis of the data is also largely complete. As of February 2023, drafting of a publication has begun. Contributions: design of the experiment, selection and preparation of samples, analysis of the XRD data after processing of the raw data by NIST. |
Collaborator Contribution | Information concerning the performance, operation and cost of superconducting TES arrays. Support of planning the experimental campaign. Processing of the raw data to establish the energy-scale calibration. |
Impact | No outcomes as yet (publication in preparation). Disciplines involved: superconducting sensors and readout electronics, x-ray diffraction, x-ray physics |
Start Year | 2016 |
Description | Corrosion analysis of Mary Rose cannonballs using handheld XRD and synchrotron XRD |
Organisation | Mary Rose Trust |
Country | United Kingdom |
Sector | Charity/Non Profit |
PI Contribution | We are investigating the capabilities of a prototype handheld XRD instrument in the analysis of the corrosion of iron-based cultural heritage artefacts, specifically applied to cannonballs from the Mary Rose. The contribution has been the provision of the prototype instrument, data acquisition and processing. In addition, we are sourcing pure mineral samples to make up representative mixtures for comparative measurements. We have also conducted non-destructive synchrotron XRD measurements on the same samples (analysis yet to be done). |
Collaborator Contribution | Provision of samples in the form of Mary Rose cannonballs (or fragments).Interpretation of the results from a cultural heritage perspective, especially relating to the conservation of iron artefacts. |
Impact | No outcomes as yet. Highly multidisciplinary - X-ray physics, materials analysis by XRD and XRF (mineralogical and elemental analyses), cultural heritage and conservation. |
Start Year | 2017 |
Description | Corrosion analysis of Mary Rose cannonballs using handheld XRD and synchrotron XRD |
Organisation | University College London |
Department | Institute of Archaeology |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | We are investigating the capabilities of a prototype handheld XRD instrument in the analysis of the corrosion of iron-based cultural heritage artefacts, specifically applied to cannonballs from the Mary Rose. The contribution has been the provision of the prototype instrument, data acquisition and processing. In addition, we are sourcing pure mineral samples to make up representative mixtures for comparative measurements. We have also conducted non-destructive synchrotron XRD measurements on the same samples (analysis yet to be done). |
Collaborator Contribution | Provision of samples in the form of Mary Rose cannonballs (or fragments).Interpretation of the results from a cultural heritage perspective, especially relating to the conservation of iron artefacts. |
Impact | No outcomes as yet. Highly multidisciplinary - X-ray physics, materials analysis by XRD and XRF (mineralogical and elemental analyses), cultural heritage and conservation. |
Start Year | 2017 |
Description | Cultural Heritage with Dr Andrew Shortland |
Organisation | British Museum |
Country | United Kingdom |
Sector | Public |
PI Contribution | Non-destructive X-ray diffraction (XRD) analysis of archaeological objects using a novel XRD technique which is insensitive to the sample morphology. X-ray fluorescence (XRF) analysis of the same objects. Interpretation of the XRD/XRF data in terms of composition. |
Collaborator Contribution | Provision of samples for XRD analysis and expert interpretation of the archaeological significance of the compositional analysis. |
Impact | No outcomes as yet. A paper has been published in the prestigious Advances section of Acta Crystallographica A journal. Highly multidisciplinary - X-ray physics, materials analysis by XRD and XRF (mineralogical and elemental analyses), archaeological. |
Start Year | 2014 |
Description | Cultural Heritage with Dr Andrew Shortland |
Organisation | Cranfield University |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | Non-destructive X-ray diffraction (XRD) analysis of archaeological objects using a novel XRD technique which is insensitive to the sample morphology. X-ray fluorescence (XRF) analysis of the same objects. Interpretation of the XRD/XRF data in terms of composition. |
Collaborator Contribution | Provision of samples for XRD analysis and expert interpretation of the archaeological significance of the compositional analysis. |
Impact | No outcomes as yet. A paper has been published in the prestigious Advances section of Acta Crystallographica A journal. Highly multidisciplinary - X-ray physics, materials analysis by XRD and XRF (mineralogical and elemental analyses), archaeological. |
Start Year | 2014 |
Description | Cultural Heritage with Prof Patrick Degryse |
Organisation | University of Leuven |
Country | Belgium |
Sector | Academic/University |
PI Contribution | Non-destructive X-ray diffraction (XRD) analysis of archaeological objects using a novel XRD technique which is insensitive to the sample morphology. X-ray fluorescence (XRF) analysis of the same objects. Interpretation of the XRD/XRF data in terms of composition. |
Collaborator Contribution | Provision of samples for XRD analysis and expert interpretation of the archaeological significance of the compositional analysis. Provisions of advice and feedback for a grant application to the EPSRC. |
Impact | No outcomes as yet. A paper has been published in the prestigious Advances section of Acta Crystallographica A journal. Highly multidisciplinary - X-ray physics, materials analysis by XRD and XRF (mineralogical and elemental analyses), archaeological. |
Start Year | 2014 |
Description | Conference Talk - A High-Resolution Non-Invasive XRD Technique for Cultural Heritage |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Other audiences |
Results and Impact | Presentation at the Synchrotron Radiation and Neutrons in Art and Archaeology 2018 conference of a novel X-ray diffraction method which is completely non-destructive and therefore highly applicable to archaeological and artwork research. The purpose of the presentation was to advertise this research to the cultural heritage community. One possible collaboration is a direct result of this presentation. |
Year(s) Of Engagement Activity | 2018 |
Description | Diamond science highlight - paints |
Form Of Engagement Activity | Engagement focused website, blog or social media channel |
Part Of Official Scheme? | No |
Geographic Reach | National |
Primary Audience | Professional Practitioners |
Results and Impact | Diamond science highlight showcasing the paints work. Published 25/1/22. |
Year(s) Of Engagement Activity | 2022 |