Ebook: Physics Methods in Archaeometry

The role of exact sciences in connection with Cultural Heritage now is well established and a new scientific branch has been generated: Archaeometry. Literally Archaeometry means measurement on ancient objects. It is a multidisciplinary field of investigations where the rigorous methods of exact sciences give a fundamental contribution to solving the problems associated with conservation and restoration, as well as to the study itself of Cultural Heritage. Archaeometry, as a scientific research field, involves interdisciplinary groups formed by scholars of the humanistic area (archaeologists, art historians, ...) together with scientists: physicists, chemists, mathematicians, biologists, engineers, etc.

The primary justification for the need of involving exact sciences in the field which traditionally has been in the past exclusive of Art historians must no doubt be found in the conservation and restoration activities. It is in fact quite obvious that diagnosis on nature and cause of degradation as well as addressing to possible remedies and criteria for a proper restoration and choosing the best conditions for conservation must be established on scientific basis.

The second argument which in the public opinion justifies the involvement of science with the world of Art is the confidence that scientific methods are infallible in unmasking forgeries. This is in fact partially true, provided forgeries are often proved by scientific examinations while, on the contrary, no scientific proof, and especially no single proof, can absolutely give the certainty of authenticity of a work of art.

But in our opinion the awareness of the central role of a scientific method as a support of philological and historical investigations is still very little diffused or, at least, it finds it hard to become widespread. Perhaps also because of our mentality, Physics, if compared to chemistry, which can more easily find application to the state of conservation diagnoses and restoration procedures, is more apt to find application in a context free from authentication or conservation implications. We want to stress the fact that very recently the Italian Physicists community demonstrated a strong interest in this field (for example, we recall the general session “Physics, Cultural Heritage and Society” organized at the SIF LXXXVI 2000 annual Congress).

This course of the International School of Physics “Enrico Fermi” on the physical methodologies that can be applied to the Cultural Heritage should be intended as an opportunity for young graduates in physics and diploma holders from Specialization schools, who whish to continue their activity in Archaeometry, to learn the modern physics analysis techniques employed for the Cultural Heritage with particular emphasis on the study of the Cultural Heritage itself rather than on their applications to conservation. The lectures here collected under the heading Physics Methods in Archaeometry were given by an international team of invited experts and have been oriented towards the methods suited to give what can in general be intended as material characterization. The only relevant exception being the lectures on microclimatic indoor and outdoor conservation conditions which can be considered as a fully due recognition of the importance of conservation for Cultural Heritage.

We are very grateful to the scientific secretaries, dr. A. C. Felici and dr. E. Sibilia, for their invaluable organization efforts, essential for the excellent success of the Course. We acknowledge also the warm personalized commitment of the Italian Physical Society secretary Ms. B. Alzani and her collaborators Miss R. Brigatti and Miss M. C. Pigazzini, who, with their enthusiastic and competent daily help and for having organized special memorable social events in the beautiful scenery of Varenna and Villa Monastero, made the Course a pleasant experience for all participants. Finally we thank Ms. M. Missiroli and Ms. C. Vasini of the Società Italiana di Fisica Editorial Office for their excellent and careful editorial work.

M. Martini, M. Milazzo and M. Piacentini

1. Introduction

2. Causes of colour

3. Colorimetry: some concepts

4. Instrumentation

5. Applications to actual cases

1. Introduction

2. Some data

3. Notation and terminology

4. Distances

5. transformation

6. Principal component analysis (PCA)

7. Cluster analysis and Mahalanobis distance

8. Discriminant analysis

9. Literature

Forward

Part 1: Air and artefact temperature

Part 2: Parameters describing atmospheric humidity

Part 3: the Kelvin law and the adsorption isotherms

Part 4: Impact of moisture on materials

1. Ion beams for material analysis: an introduction

2. Kinematics of RBS (Rutherford Backscattering Spectroscopy)

3. The scattering cross-sections of RBS

4. Typical RBS spectra

5. Basic principles of PIXE (Particle Induced X-ray Emission)

6. Fundamentals of PIGE (Particle Induced γ-ray Emission) and nuclear reactions

7. Identification of signals for analytical purposes

8. Experimental procedure for external beam PIXE

9. Analysis of coins

10. The soldering of gold artefacts

11. Prehispanic gold artefacts of Mesoamerica

12. Differential PIXE analysis for the study of depletion gilding

Conclusions

Introduction

The scientific research at the C2RMF

Scientific information indexing and retrieval

Digitising activities for cultural applications

New technologies for direct capture of 2D and 3D objects

The C2RMF panoramic views digitisation systems for objects consulting and 3D model construction

The 3D laser detection of objects

The 2D and 3D digitisation of paintings

The Jumbolux linear beam lighting system

A pigmented chart for colour correction of paintings

The CRISATEL high-definition digital camera

Varnish opacity, thickness and colour measurement

3D capture of paintings

Conclusion

Introduction

The nature of marble

Techniques used for provenance determination

Neutron activation analysis

Cathodoluminescence

Petrographic thin-section analysis

Stable isotope analysis

Electron Paramagnetic Resonance spectroscopy (EPR)

Ancient quarries and database

Provenance determination procedure

Sampling or not sampling?

Sampling procedure

The movement of marble in antiquity

1. Introduction

2. Thermoluminescence

3. Applied thermoluminescence

4. TL dating

5. TL dating: a few examples of application

6. Conclusions

1. Introduction

2. Quantitative XRF analysis

3. Measurement of coin fineness

4. Quantitative analysis of glass and ceramics

1. Gilding with gold foil

2. Gilding with gold leaf

3. Fire gilding

4. Depletion gilding

5. Pseudogilding

Hammered wire

Swaged wire

Block-twisted wire

Strip drawn wire

Strip twisted wire

Cast wire

Folded wire

Drawn wire

Summary

The presence of a body

Dating the burial

The analysis of the jewellery

The examination of the shield and helmet

The examination of the sceptre and of the iron standard

Bronzes in the Sutton Hoo grave

Glass in the Sutton Hoo grave

The Sutton Hoo drinking horns

Summary

Copies made from moulds of original objects

Copies made in the style of original objects

Genuine objects which have been altered to make them rarer and thus more valuable

Damaged antiquities which have been carefully restored so that the damage is invisible

Forgeries made in ancient times

The scientific detection of forgeries

Non-destructive examination

The materials of manufacture

The alteration products (such as metallic corrosion or weathering layers)

The structure of the original material and the techniques of manufacture

The age of the object

1. Introduction

2. Pigments

3. Glazes

4. Use of hard X-rays and neutrons on metal objects

5. Summary

Introduction

The behaviour of trace elements

Trace elements and technology

Trace elements and provenance

Contemporary art: characters and problems

Image spectroscopy

Principles of the method

Measurement

Experimental apparatus

Calibration

Experimental results

Treatment of spectral data

Principal Component Analysis: mathematical definitions

Applications

Conclusions

History of archaeometry in the UK

Remote sensing

Science-based dating

Artefact studies

Man and his environment

Conclusions

Reconstruction

Discovery and adoption

Mode of production

Technological choice and change

Glazed stone, faience and related materials

The beginnings of glass

Roman and Byzantine glass

Islamic and Medieval glass

The first glazed earthenware

Lead glazed pottery

Tin-opacified glazes

Related European glazed ceramics

1. Introduction

2. Accelerator mass spectrometry

3. Radiocarbon dating

4. Bomb pulse dating

5. Dating with in situ cosmogenic radionuclides

6. Conclusions

Introduction

Analytical methods and instrumentation

Spectroscopy and spectrometry

Principles and prerequisites of provenance studies

Sample selection and other considerations

Trade and exchange

Obsidian sourcing in the central Mediterranean: a case study

Discussion and conclusion

Introduction

Principles of stable isotope analysis

Analytical methods

Recent applications

Strontium isotope analysis

Nuclear clocks

Luminescence dating

TL dating of heated flint

OSL dating of colluvium

Spatially resolved luminescence

Fission track dating

Alpha recoil track dating

1. Introduction: the computed tomography technique

2. The micro-CT system

3. Intensified 3D tomography large-area system I

4. Intensified 3D tomography large-area system II

5. Fan beam tomography with an intensified linear detector

6. Conclusions