Front Cover
Copyright Page
CONTENTS
PREFACE
1: INTRODUCTION TO ARCHAEOLOGICAL CERAMICS & COMPOSITIONAL ANALYSIS
1.1 Archaeological Ceramics
1.2 Ceramic Compositional Analysis
1.3 Introduction to Thin Section Petrography
1.4 Further Reading
Figures (Chapter 1)
Fig. 1.1 Archaeological ceramics
Fig. 1.2 Life-size ceramic figurines
Fig. 1.3 Ceramic building material
Fig. 1.4 Ceramic sherds in situ in archaeological strata.
Fig. 1.5 Pottery sherd being studied by eye
Fig. 1.6 Dedicated scientific laboratory for the materials science analysis of archaeological ceramics
Fig. 1.7 Archaeological ceramic sherd seen in thin section under the polarising light microscope
Fig. 1.8 Diffractogram of the mineralogical composition of two archaeological ceramic sherds
Fig. 1.9 Geochemical data on the abundance of 23 elements in 50 archaeological ceramic sherds
Fig. 1.10 Archaeological ceramic sherd seen in polished cross section with the scanning electron microscope (SEM) in backscattered electron mode (BSE)
Fig. 1.11 Compositional patterning within archaeological ceramics from a single site, as seen in thin section
Fig. 1.12 Statistical exploration of geochemical data on nine elements collected on 56 ceramic artefacts of the type in Fig. 1.2
Fig. 1.13 Ceramic provenance determination
Fig. 1.14 Reconstructed paste preparation technology for the production of multiple ceramic types at Emperor Qin Shihuang’s mausoleum near Xi’an, China
Fig. 1.15 Clay vitrification microstructure of archaeological ceramic sherds in the SEM
Fig. 1.16 Simple, inexpensive polarising light microscope being used to examine an archaeological ceramic thin section
Fig. 1.17 Archaeological ceramic sherd being non-invasively geochemically characterised via portable X-ray fluorescence spectroscopy (pXRF)
Fig. 1.18 Archaeological ceramic thin sections
Fig. 1.19 An archaeological ceramic thin section seen at high magnification under the light microscope in plane polarised light (PPL)
Fig. 1.20 The same sample as Fig. 1.19 above, but seen in crossed polars (XP)
Fig. 1.21 Archaeological ceramic sherd with plant matter added to its paste
Fig. 1.22 Used ancient refractory ceramic in thin section
Fig. 1.23 Fritware/stonepaste ceramic artefact in thin section composed of angular, crushed quartz inclusions set in a glassy, isotropic matrix with abundant voids
Fig. 1.24 Photomicrograph of cementitious material in thin section
2: SAMPLING, PREPARATION & ANALYSIS OF CERAMIC THIN SECTIONS
2.1 Introduction
2.2 Sampling
2.3 Thin Section Preparation
2.4 Analytical Equipment
2.5 Other Resources
2.6 Curation & Access to Thin Sections
2.7 Further Reading
Figures (Chapter 2)
Fig. 2.1 Thin section production sequence
Fig. 2.2 Sub-sampling archaeological ceramics for thin section petrography at a museum
Fig. 2.3 Orientation of ceramic thin sections
Fig. 2.4 Apparatus for cutting ceramics during thin section preparation
Fig. 2.5 Archaeological ceramic sherd thin sectioned twice
Fig. 2.6 Archaeological ceramic sherd thin sectioned twice
Fig. 2.7 Sensitively sampling a complete ceramic artefact for thin section preparation
Fig. 2.8 Plucking of a ceramic thin section due to insufficient impregnation of the chip during preparation
Fig. 2.9 Polishing impregnated ceramic chips on a rotating lapping device
Fig. 2.10 Two models of commercially available thin sectioning machines
Fig. 2.11 Fine scratches left from grinding the sample with the diamond cup wheel of a thin section machine
Fig. 2.12 This coverslipped thin section is more than 30 μm thick
Fig. 2.13 Final polishing thin sections by hand
Fig. 2.14 The upper part of this thin section is <30 μm thick
Fig. 2.15 This sample contains dark carborundum grit particles that have accumulated in voids during polishing and were not removed before coverslipping
Fig. 2.16 SEM micrograph of carbon-coated, non-coverslipped, diamond-polished archaeological ceramic thin section in backscattered electron mode
Fig. 2.17 Small air bubbles have been trapped in the optical adhesive used to fix the coverslip to this thin section
Fig. 2.18 Blue dye has been added to the epoxy resin used to impregnate this sample
Fig. 2.19 The carbonates in this ceramic thin section have been stained using Dickson’s Method
Fig. 2.20 Petrographic microscope fitted with a mechanical stepping stage and a point-counting machine for quantitative petrographic analysis
Fig. 2.21 Field microscope for the analysis of geological, archaeological and environmental thin sections
Fig. 2.22 Photomicrograph of ceramic thin section taken under circular polarisation
Fig. 2.23 Bone inclusions seen in thin section under a fluorescence microscope
Fig. 2.24 Bone inclusions seen in white light under XP
Fig. 2.25 Archaeological ceramic sample viewed in XP with lambda plate inserted
Fig. 2.26 Geological maps and field guides
Fig. 2.27 The digital photomicrograph in Fig. 2.26 below has been subjected to image analysis in order to pick out and ‘segment’ the inclusions (white), matrix (brown) and voids (black)
Fig. 2.28 Compare this photomicrograph with Fig. 2.25 above in which it has been subjected to a filtering processes in order to pick out the inclusions, matrix and voids
Fig. 2.29 A ceramic thin section collection
Fig. 2.30 Screenshot of on-line database for archaeological surveys and image collections
3: COMPOSITION OF ARCHAEOLOGICAL CERAMICS IN THIN SECTION
3.1 Introduction
3.2 The Clay Matrix
3.3 Particulate Inclusions
3.4 Voids
3.5 Further Reading
Figures (Chapter 3)
Fig. 3.1 The three components of archaeological ceramics in thin section can be seen in this image
Fig. 3.2 The same sample as Fig. 3.1 above, but in XP
Fig. 3.3 This ceramic sample has a fine homogeneous ‘clean’ clay-rich matrix that is easily distinguishable from the rare silt and sand-sized inclusions
Fig. 3.4 Clay matrix at high magnification with fine inclusions <10 μm in diameter that are too small to be studied in detail and are therefore included in the matrix
Fig. 3.5 Natural heterogeneity in the clay matrix most likely deriving from the use of variegated clay
Fig. 3.6 Heterogeneity in the clay matrix caused by the deposition of secondary calcite by groundwater
Fig. 3.7 The clay source used to make this sample contains abundant fine microcrystalline calcite that gives the clay matrix a light yellow-brown colour
Fig. 3.8 Very fine-grained archaeological ceramic sample
Fig. 3.9 Coarse-grained archaeological ceramic sample in thin section
Fig. 3.10 The feldspar inclusion in the centre is weathered and contains fine-grainedsericite mica
Fig. 3.11 Inclusions of the common mineral quartz
Fig. 3.12 Inclusions of the mineral plagioclase feldspar
Fig. 3.13 Inclusions of the mineral biotite mica
Fig. 3.14 Inclusion of the mineral muscovite mica
Fig. 3.15 Inclusions of the mineral hornblende
Fig. 3.16 Inclusions of the mineral clinopyroxene
Fig. 3.17 Inclusions of the mineral calcite
Fig. 3.18 Inclusions of the mineral talc
Fig. 3.19 Fragments of plutonic igneous rock composed of quartz, plagioclase and alkali feldspar and biotite
Fig. 3.20 An inclusion of granitic igneous rock is visible on the left of this sample
Fig. 3.21 Inclusions of fine grained volcanic igneous rock
Fig. 3.22 Inclusions of volcanic ash
Fig. 3.23 Inclusion of clastic sedimentary rock
Fig. 3.24 Inclusion of clastic sedimentary rock
Fig. 3.25 Inclusions of carbonate sedimentary rock
Fig. 3.26 Inclusion of siliceous sedimentary rock
Fig. 3.27 Elongate inclusions of low-grade metamorphic rock
Fig. 3.28 Inclusion of medium-grade metamorphic rock
Fig. 3.29 Inclusions of hydrothermally altered metamorphic rock
Fig. 3.30 Inclusions of metamorphic rock composed of quartz, biotite mica and needle-shaped crystals of the mineral sillimanite
Fig. 3.31 The broken shell fragments in this sample derive from recent freshwater mussels
Fig. 3.32 Several globular chambered foraminifer microfossils are visible in this sample which was made from calcareous marine clay or ‘marl’
Fig. 3.33 The small circular feature in the centre of this image is a specimen of the calcareous nannofossil species Watznaueria barnesiae.
Fig. 3.34 This sample contains abundant sponge spicules
Fig. 3.35 A diatom frustule can be seen at high magnification in this sample
Fig. 3.36 Several transparent phytoliths are visible in this sample
Fig. 3.37 The bone fragments in this image have a fibrous microstructure with small spherical ‘osteocytes'
Fig. 3.38 Carbonised remains of plant inclusions within curved voids occur in this sample
Fig. 3.39 Rice husk inclusions
Fig. 3.40 Carbonised remains of wood fragment in ceramic core of bronze statue
Fig. 3.41 Pollen grains seen at high magnification in low fired experimental ceramic sample
Fig. 3.42 Numerous fragments of intentionally added crushed pottery or ‘grog’ are visible in this sample
Fig. 3.43 Grog inclusion with a relic surface from the pottery vessel or other ceramic object that it came from
Fig. 3.44 The large grog inclusion in this sample contains sand temper that was added to the parent vessel from which it originates
Fig. 3.45 The two small grog inlcusions visible in this sample have shrinkage voids around part of their margins
Fig. 3.46 This angular glassy vesicular inclusion is a fragment of fuel ash slag from the melting of some sort of metallurgical ceramic object
Fig. 3.47 Clay-rich plastic inclusion
Fig. 3.48 Indistinct plastic clay feature
Fig. 3.49 Unidentifiable weathered inclusion
Fig. 3.50 This sample contains abundant opaque inclusions that are composed of ferruginous minerals such as hematite or magnetite
Fig. 3.51 Opaque nodules containing quartz clasts
Fig. 3.52 Concentric iron-rich pedogenic nodule or ‘pisolith’
Fig. 3.53 Branching elongate voids between adjacent lumps or crumbs of clay
Fig. 3.54 Thin parallel elongate voids resulting from drying
Fig. 3.55 Decomposition of carbonate inclusions
Fig. 3.56 The many spherical vesicles in this sample are bloating pores resulting from the release of gases by the breakdown of the clay matrix at very high temperatures
Fig. 3.57 Distinctive pseudomorphic voids left by the post-depositional dissolution of soluble inclusions
Fig. 3.58 Holes resulting from poor thin section manufacture
Fig. 3.59 Holes resulting from poor thin section manufacture
Fig. 3.60 Secondary calcite coating within void
Fig. 3.61 Gypsum precipitated within a vugh-shaped void in ceramic during burial
Fig. 3.62 Phosphate deposited within voids during burial
4: CLASSIFICATION & CHARACTERISATION OF ARCHAEOLOGICAL CERAMICS IN THIN SECTION
4.1 Introduction
4.2 Visual Classification & Description
4.2.1 Grouping
4.2.2 Description
4.2.2.1 A Petrographic Fabric Description System
4.2.2.2 Inclusions
4.2.2.3 Clay Matrix
4.2.2.4 Voids
4.2.2.5 Comments Section/Fabric Summary
4.2.2.6 Example Unimodal Fabric Description
4.2.2.7 Example Bimodal Fabric Description
4.2.2.8 Example Fabric Summary
4.3 Quantitative Characterisation & Statistical Grouping
4.3.1 Textural Analysis
4.3.2 Modal Analysis
4.3.3 Data Collection
4.3.4 Statistical Classification
4.4 Macroscopic Fabric Analysis
4.4.1 Equipment & Sample Preparation
4.4.2 Macroscopic Fabric Characterisation
4.4.3 Macroscopic Classification/Grouping
4.4.4 Macroscopic Fabric Description
4.5 Further Reading
Figures (Chapter 4)
Fig. 4.1 The inclusions, clay matrix and voids that can be clearly distinguished in this sample each have specific compositional, textural, shape and microstructural characteristics
Fig. 4.2 The streaks of darker clay within this sample are features that cannot be effectively characterised quantitatively, but can described via words and specialist terminology
Fig. 4.3 Nine different archaeological ceramic samples seen in thin section
Fig. 4.4 The thin sections in Fig. 4.3 above have been sorted into fabrics
Fig. 4.5 Manual visual grouping of archaeological ceramic thin sections
Fig. 4.6 Two compositionally related samples (1 & 7) from the assemblage in Figs. 4.3 & 4.4, which belong to the same fabric, but were fired under different atmospheric conditions, leading to a clear contrast in the colour of their clay matrices
Fig. 4.7 Representative samples from two related fabrics
Fig. 4.8 Representative samples from two sub-fabrics
Fig. 4.9 Comparison chart for the visual estimation of percentage area
Fig. 4.10 Experimental ceramic sample in which 50% by volume of sand temper has been added to fine natural clay
Fig. 4.11 Ceramic sample with equant, generally rounded inclusions of quartz and glauconite
Fig. 4.12 Ceramic sample with elongate, angular inclusions of volcanic ash
Fig. 4.13 Categories for the description of shape and roundness/angularity in clastic sedimentary grains
Fig. 4.14 Strong alignment of elongate inclusions parallel to the margins of a ceramic artefact
Fig. 4.15 Poor alignment of elongate inclusions parallel to the margins of a ceramic artefact
Fig. 4.16 Relic coil picked out by concentric alignment of elongate inclusions
Fig. 4.17 Comparison chart for estimating the degree of sorting in clastic sediments andsedimentary rocks
Fig. 4.18 Well sorted inclusions
Fig. 4.19 Poorly sorted inclusions
Fig. 4.20 The inclusions in this coarse fabric are poorly sorted
Fig. 4.21 Composite rock fragment inclusions
Fig. 4.22 Pottery fabric containing schist fragments plus mineral inclusions of quartz and muscovite mica deriving from the same rock
Fig. 4.23 Terminology from soil micromorphology used for the characterisation of argillaceous inclusions in ceramics
Fig. 4.24 Rounded plastic argillaceous inclusions (clay pellets) with neutral optical density and sharp to diffuse boundaries, which are discordant with the rest of the fabric
Fig. 4.25 Grog fragment with visible internal fabric containing green amphibole inclusions
Fig. 4.26 Indistinct clay feature with merging boundaries that is best described as heterogeneity within the clay matrix rather than as a plastic inclusion
Fig. 4.27 Ceramic specimen with calcareous clay matrix
Fig. 4.28 Ceramic specimen with non-calcareous clay matrix
Fig. 4.29 Patchy secondary calcite within otherwise non-calcareous clay matrix
Fig. 4.30 Clay matrix with relatively low proportion of iron
Fig. 4.31 Colour variation in the clay matrix resulting from uneven firing conditions
Fig. 4.32 Heterogeneous clay matrix containing streaks and laminae of darker and lighterclay
Fig. 4.33 Optically active clay matrix
Fig. 4.34 Terminology for the description of void shape in archaeological ceramic thinsections.
Fig. 4.35 Two spherical, rounded voids can be seen in the top left and bottom right of centre of this image
Fig. 4.36 Elongate parallel-sided voids with tapering ends
Fig. 4.37 Irregular-shaped void that is neither spherical nor has parallel sides
Fig. 4.38 Ring void formed around inclusion during firing
Fig. 4.39 Characteristic voids left from the destruction of plant matter during firing
Fig. 4.40 Irregular fracture void formed after firing
Fig. 4.41 Photomicrograph of the Phyllite Fabric described in Section 4.2.2.6
Fig. 4.42 Photomicrograph of the Phyllite Fabric described in Section 4.2.2.6
Fig. 4.43 Photomicrograph of the bimodal Sand-Tempered Silty Micaceous Fabric described in Section 4.2.2.7
Fig. 4.44 Photomicrograph of the bimodal Sand-Tempered Silty Micaceous Fabric described in Section 4.2.2.7
Fig. 4.45 Photomicrograph of the Grog Tempered Fine Sedimentary Fabric described in Section 4.2.2.8
Fig. 4.46 Photomicrograph of the Grog Tempered Fine Sedimentary Fabric described in Section 4.2.2.8
Fig. 4.47 Individual grain size measurements of inclusions in an archaeological ceramic thin section
Fig. 4.48 Frequency distribution chart of the inclusion grain size data above
Fig. 4.49 Ternary diagram displaying modal data on the relative proportions of inclusions, matrix and voids in different ceramic categories from a single site
Fig. 4.50 Two archaeological ceramic samples manufactured from a similar coarse residual granitic clay source, but displaying different degrees of disaggregation of the naturally occurring inclusions
Fig. 4.51 Gazzi-Dickinson method of modal analysis
Fig. 4.52 Grain size frequency distribution chart of inclusions with modal data included
Fig. 4.53 Procedures for the collection of quantitative data from archaeological ceramic thin sections
Fig. 4.54 Area counting via automated image analysis
Fig. 4.55 Modern point counting microscope set up
Fig. 4.56 Grain size distribution histogram with corresponding cumulative curve in green
Fig. 4.57 Rose diagrams of inclusion orientation plotted from long axes measurements during textural analysis of ceramic thin sections
Fig. 4.58 Quantitative petrographic data from the modal analysis of 12 ceramic thin sections with patterning indicated
Fig. 4.59 Automated classification of the multivariate quantitative petrographic data in Fig. 4.58 via principal component analysis (PCA).
Fig. 4.60 Hierarchical cluster analysis of the multivariate quantitative petrographic data in Fig. 4.56
Fig. 4.61 Principal component analysis score plot of geochemical data with samples labelled according to quantitative petrographic data
Fig. 4.62 Cluster analysis of geochemical data on ceramic samples with chemical clusters (I-IX) and petrographic classification (1-12; A-J)
Fig. 4.63 Analyst studying the fabric of pottery sherds macroscopically in hand-specimen using a binocular reflected light microscope
Fig. 4.64 The fabric of a pottery sherd seen in hand specimen on a fresh break
Fig. 4.65 The fabric of the same ceramic sherd as Fig. 4.64 above, seen at higher magnification in thin section, demonstrating the greater resolution available compared to macroscopic analysis
Fig. 4.66 Individual inclusions cannot be made out in the fabric of this fine sherd
Fig. 4.67 Macroscopic fabric analysis being carried out using a low magnification digital reflected light microscope plugged directly into a computer
Fig. 4.68 The fabric of this sherd differs in colour between the core and the margins, due to variation in the oxidation state of iron during firing
Fig. 4.69 Udden-Wentworth comparison chart for the grain size estimation of inclusions in ceramics in hand specimen
Fig. 4.70 Inclusions of shell can be seen in the fabric of this coarse sherd
Fig. 4.71 Inclusions of flint can be seen in the fabric of this coarse sherd
Fig. 4.72 Inclusions of grog can be seen in the fabric of this coarse sherd
Fig. 4.73 Inclusions of igneous rock can be seen in the fabric of this coarse sherd
Fig. 4.74 The clay matrix of this fabric contains a high proportion of calcite and a low amount of iron, giving it a light colour
Fig. 4.75 A distinctive rhombohedral void can be seen in the fabric of this sherd
5: PETROGRAPHIC PROVENANCE DETERMINATION
5.1 Introduction
5.2 Geological Characterisation of Ceramic Raw Materials
5.3 Provenance Resolution
5.4 Geological Literature & Fieldwork
5.5 Quantitative Provenance Determination
5.6 Micropalaeontology
5.7 Interpreting Provenance Data
5.8 Further Reading
Figures (Chapter 5)
Fig. 5.1 This sample was almost certainly manufactured in an area that contains low-grade metamorphic rocks.
Fig. 5.2 This sample has a very different petrographic composition to that above and is therefore likely to have been produced in a different location
Fig. 5.3 Local and non-local ceramic fabrics from a small Aegean island characterised by limestone and metamorphic bedrock
Fig. 5.4 Quantitative geographic distribution of petrographic fabrics
Fig. 5.5 Residual clay source
Fig. 5.6 Sedimentary clay deposit
Fig. 5.7 Residual clay collected from the primary deposit pictured in Fig. 5.5
Fig. 5.8 Sedimentary clay collected from the secondary deposit pictured in Fig. 5.6
Fig. 5.9 Laminated sedimentary clay source with fine-scale compositional and colour variation
Fig. 5.10 The paste of this sample is likely to have been produced from residual clay formed on coarse-grained, plutonic, acid-intermediate igneous rock such as granodiorite
Fig. 5.11 The paste of this sample is likely to have been produced from fine sedimentary clay with almost no silt or sand sized clasts
Fig. 5.12 Coarse ware ceramic sample with large, readily identifiable volcanic inclusions
Fig. 5.13 Fine ware ceramic containing only very small inclusions of quartz and mica
Fig. 5.14 The fabric of this sherd is dominated by quartz inclusions
Fig. 5.15 The fabric of this sample is characterised by the presence of dolerite inclusions
Fig. 5.16 Geological map, with topography, rivers, roads and place names overlain by distribution of major bedrock units
Fig. 5.17 Stylistic groups of Bronze Age transport jars from the site of Kommos, Greece
Fig. 5.18 Petrographic ‘reference groups’ and matches
Fig. 5.19 Interpreted sources of Canaanite Jars from the Bronze Age from the site of Kommos, Greece
Fig. 5.20 Comparison of petrographic fabrics (coloured) with statistical classification of geochemical data (clusters 1-5)
Fig. 5.21 Raw material prospecting or ‘clay sampling’ for ceramic provenance determination via ceramic petrography
Fig. 5.22 Sampling potential ceramic raw material source in the field
Fig. 5.23 Testing a potential source of ceramic raw material in the field
Fig. 5.24 Archaeological ceramic sample with sand-sized inclusions of several mineralogical and lithological origins
Fig. 5.25 Schematic representation of the composition, size and shape of clasts in river alluvium and their relationship to underlying geology
Fig. 5.26 Fired test pieces or ‘briquettes’ of clay samples that were collected in the field and processed in the laboratory
Fig. 5.27 Compositional match between fired briquette of potential raw material sample (left) and local archaeological ceramic sample (right)
Fig. 5.28 Database of ceramic raw materials for provenance determination
Fig. 5.29 Archaeological ceramic fabric characterised by elongate foliated limestone inclusions added to red-firing iron-rich clay source
Fig. 5.30 Replicated clay paste of the ceramic fabric in Fig. 5.29 above, using local terra rossa soil and crushed limestone collected close to the site
Fig. 5.31 Petrofacies model of Tucson Basin, Arizona
Fig. 5.32 Dating ceramic raw materials using calcareous nannofossil biostratigraphy
Fig. 5.33 Isolated calcareous nannofossil specimens (arrows) in smear slides prepared from archaeological ceramic samples
Fig. 5.34 Reconstructed seasonal movement of prehistoric hunter-gatherer populations based on petrographic provenance
Fig. 5.35 Probable origins of Neolithic pottery from ritual cave site on the island of Yioura, Greece
Fig. 5.36 Quantitative geographic distribution of petrographic fabrics
6: RECONSTRUCTING ANCIENT CERAMIC TECHNOLOGY IN THIN SECTION
6.1 Introduction
6.2 Raw Material Selection & Procurement.
6.3 Raw Material Processing & PastePreparation
6.3.1 Reduction and Refining
6.3.2 Tempering
6.3.3 Clay Mixing
6.3.4 Hydration, Ageing & Working
6.4 Forming Methods
6.5 Finishing
6.6 Drying
6.7 Firing
6.7.1 Firing Temperature
6.7.2 Atmosphere of Firing
6.7.3 Firing Regime
6.8 Ceramic Use & Function
6.9 Post-Depositional Alteration of Archaeological Ceramics
6.10 Further Reading
Figures (Chapter 6)
Fig. 6.1 Reconstructing ceramic technology in thin section
Fig. 6.2 Ceramic ethnoarchaeology
Fig. 6.3 Experimental archaeology as a tool for the study of ancient ceramic technology
Fig. 6.4 Engineering materials science test of experimental ceramic sample in the laboratory
Fig. 6.5 In this sample crushed pottery temper (centre and upper middle) has been added to naturally lean residual clay with abundant aplastic inclusions.
Fig. 6.6 This sample has been tempered with dark brown crushed sherds (upper) andangular quartz-rich sand
Fig. 6.7 The production sequence or ‘chaîne opératoire’ of a ceramic vessel
Fig. 6.8 Several argillaceous particles are present in this sample, which are likely to be small grains left from the grinding of dry clay
Fig. 6.9 Experimental sample of ground-up ancient marine mudstone
Fig. 6.10 Remains of carbonised plant matter
Fig. 6.11 Coarse naturally sandy unrefined clay source with poorly sorted grain size distribution (based on measurement of 50 grains)
Fig. 6.12 The same clay source in Fig. 6.11 above, after removal of coarse grains via settling
Fig. 6.13 Probable refined clay paste
Fig. 6.14 The angular inclusions visible in this sample derive from coarse grained metamorphic rock that was probably crushed before being added as temper to fine base clay
Fig. 6.15 Weathered coarse grained metamorphic rock occurring at the native campsite from which the sherd in Fig. 6.14 above was excavated
Fig. 6.16 This sample contains fragments of the shells of brachipod molluscs that are likely to have been crushed and added as temper to prepare the paste
Fig. 6.17 The angular inclusions in this sample are fragments of bone temper, which was crushed before its addition to the paste
Fig. 6.18 This experimental sample has been made by the addition of crushed freshwater sponge to fine clay
Fig. 6.19 This sample contains voids with blackened margins left by the destruction of plant matter during firing
Fig. 6.20 Tree bark has been added as temper to the paste of this sample
Fig. 6.21 In this sample a significant quantity of crushed pottery or ‘grog’ fragments have been added as temper
Fig. 6.22 Slag temper
Fig. 6.23 Compositional mismatch between two main inclusion types indicating the presence of temper
Fig. 6.24 Ceramic made with naturally silty calcareous clay source displaying unimodal skewed grain size distribution
Fig. 6.25 Ceramic made with the same clay source as that in Fig. 6.24 above, but with added sand temper
Fig. 6.26 Ceramic sherd with clear bimodal grain size distribution
Fig. 6.27 Naturally sandy clay source with unimodal skewed grain size distribution
Fig. 6.28 This sample contains flint temper added to a quartz-rich silty clay source
Fig. 6.29 Crushed limestone temper
Fig. 6.30 The angular inclusions visible in this sample derive from coarse grained igneous rock such as granite that was crushed and added as temper to fine base clay
Fig. 6.31 Incomplete blending of temper
Fig. 6.32 Incomplete blending of temper
Fig. 6.33 This sample has been tempered with two different types of aplastic particulate material
Fig. 6.34 This paste has been prepared by dry mixing dark and light coloured clay, resulting in a streaked texture and the presence of semi-plastic bodies
Fig. 6.35 Heterogeneity left by the intentional mixing of two different clay sources
Fig. 6.36 Argillaceous bodies resulting from probable clay mixing
Fig. 6.37 Streaking in naturally heterogeneous clay
Fig. 6.38 Heterogeneity in coarse ceramic building material that could represent the use of naturally variable clay that was not sufficiently homogenised
Fig. 6.39 Streak, lens and possible body of dark clay that could be due to clay mixing, but may also be rare natural phenomena
Fig. 6.40 Remnant granules of powdered clay that were not sufficiently wetted during hydration of the paste
Fig. 6.41 Macro traces of ceramic forming seen on the surface of a sherd
Fig. 6.42 Experimental wheel thrown pot made from paste tempered with chopped straw, fired and cut in a horizontal, vertical and tangential direction
Fig. 6.43 Horizontal thin section through the wall of a wheel thrown experimental pot tempered with mussel shell
Fig. 6.44 Vertical thin section through the wall of a wheel thrown experimental pot tempered with mussel shell
Fig. 6.45 Tangential thin section through the wall of a wheel thrown experimental pot tempered with mussel shell
Fig. 6.46 The equant sand temper inclusions in this wheel thrown sample do not exhibit strong alignment in vertical section
Fig. 6.47 Experimental pinch pot made from paste tempered with chopped straw, fired and cut in a horizontal, vertical and tangential direction
Fig. 6.48 Vertical thin section through the wall of a hand-drawn experimental pot tempered with mussel shell
Fig. 6.49 Horizontal thin section through the wall of a hand-drawn experimental pot tempered with mussel shell
Fig. 6.50 Tangential thin section through the wall of a hand-drawn experimental pot tempered with elongate mussel shell
Fig. 6.51 Experimental slab built pot made from paste tempered with chopped straw, fired and cut in a horizontal, vertical and tangential direction
Fig. 6.52 Horizontal thin section through the wall of a slab-built experimental pot tempered with mussel shell
Fig. 6.53 Vertical thin section through the wall of a slab-built experimental pot tempered with mussel shell
Fig. 6.54 Vertical thin section through the wall of a slab-built pot tempered with mussel shell
Fig. 6.55 Tangential thin section through the wall of a slab-built experimental pot tempered with mussel shell
Fig. 6.56 Possible remains of parting material left on the surface of a sherd of a mould-made pot
Fig. 6.57 Experimental coil-built pot made from paste tempered with chopped straw, fired and cut in a horizontal, vertical and tangential direction
Fig. 6.58 Vertical thin section through the wall of a coil-built experimental pot tempered with mussel shell
Fig. 6.59 Relic coil seen in a vertical thin section
Fig. 6.60 This vertical thin section contains at least two relic coils picked out by the orientation of the coarse elongate inclusions
Fig. 6.61 Relic coils indicated by firing in a vertical thin section
Fig. 6.62 Horizontal thin section through the wall of a coil-built experimental pot tempered with mussel shell
Fig. 6.63 Tangential thin section through the wall of a coil-built experimental pot tempered with mussel shell
Fig. 6.64 Self-slip on exterior of ceramic. A thin subtle layer of fine clay is visible on the margin of this sample
Fig. 6.65 The flat straight margin at the top of this sample is a burnished surface
Fig. 6.66 Incised decoration on surface of archaeological ceramic
Fig. 6.67 A layer of iron-poor clay slip has been applied to the exterior of this sample to give it a light coloured surface
Fig. 6.68 Red non-calcareous slip layer applied to red-firing non-calcareous clay body
Fig. 6.69 Light coloured calcareous slip applied to red-firing non-calcareous clay body Neolithic pottery, Greece
Fig. 6.70 Slip and paint
Fig. 6.71 Transparent external glaze layer. Some vesicles are visible within the glaze in this image
Fig. 6.72 Under crossed polars the transparent glaze layer in the sample above has an isotropic black colour
Fig. 6.73 Coloured glaze seen in thin section
Fig. 6.74 Transparent glaze applied on top of slip layer
Fig. 6.75 Quartz and feldspar inclusions in fritted ‘glaze’
Fig. 6.76 Parallel elongate voids resulting from stresses caused during drying
Fig. 6.77 Parallel elongate voids formed during drying
Fig. 6.78 The grog particles in this sample are picked out by thin ring voids caused by the shrinkage of the parent clay during drying and/or firing
Fig. 6.79 Optically active clay matrix
Fig. 6.80 In this image, the sample in Fig. 6.79 above has been rotated through 45°
Fig. 6.81 Optically inactive clay matrix
Fig. 6.82 In this image, the sample in Fig. 6.81 above has been rotated through 45°
Fig. 6.83 Alteration of amphibole during firing
Fig. 6.84 Alteration of serpentinite during firing
Fig. 6.85 Alteration of glauconite during firing
Fig. 6.86 Behaviour of calcite during firing
Fig. 6.87 Behaviour of calcite during firing
Fig. 6.88 The limestone inclusions in this sample have been altered during the firing process, leaving voids
Fig. 6.89 Highly fired calcareous clay
Fig. 6.90 Bloating due to over-firing
Fig. 6.91 Oxidised ceramic sample
Fig. 6.92 Reduction fired ceramic sample
Fig. 6.93 Dark core due to insufficient penetration of oxygen during firing
Fig. 6.94 Metallurgical slag formed on refractory ceramic artefact during its use
Fig. 6.95 Bloating of refractory ceramic due to use at very high temperature
Fig. 6.96 Alteration of feldspar during use
Fig. 6.97 Superficial earthy encrustation on the exterior of an artefact from its burialin the archaeological record
Fig. 6.98 Bioencrustation of ceramic artefact buried in a marine environment
Fig. 6.99 Distinctive pseudomorphic voids left by the post-depositional dissolution of soluble inclusions
Fig. 6.100 Rhombohedral sparry calcite temper inclusions have been preferentially dissolved from the margins of this sample during burial
Fig. 6.101 The calcite inclusion in the centre of this sample has broken down during firing and the altered calcareous material has then been redistributed within the sample by groundwater
Fig. 6.102 Calcareous fringe deposited on the interior surface of voids
Fig. 6.103 The thin ring void around the quartz inclusion in this sample is infilled with secondary calcite, as are several small elongate voids
Fig. 6.104 Diffuse secondary calcite
Fig. 6.105 Layering visible in ceramic recovered from marine environment caused by the deposition of secondary calcite, particularly in the margins of the sherd
Fig. 6.106 Layer of gypsum crystals deposited on the surface of archaeological ceramic
Fig. 6.107 The mottling in this sample is due to the deposition of iron within fine voidsduring burial
Fig. 6.108 Iron-rich secondary deposit within voids
7: OTHER CERAMIC MATERIALS IN THIN SECTION
7.1 Introduction
7.2 Architectural Ceramics
7.3 Unfired Clay Structures
7.4 Refractory Ceramics
7.5 Other Ceramic Objects
7.6 Petrography of Cementitious Materials
7.7 Stoneware, Fritware, Porcelain & Faience
7.8 Further Reading
Figures (Chapter 7)
Fig. 7.1 Coarse heterogeneous, poorly-mixed fabric of ceramic building material
Fig. 7.2 This ceramic building material was made by the admixture of dark inclusion-poor clay, of which two remnant lumps are visible, plus siltier material
Fig. 7.3 Addition of temper to clay paste of ceramic building material
Fig. 7.4 The abundant, fine, well-sorted quartz and mica inclusions in this architectural ceramic sample suggest that its paste was refined
Fig. 7.5 Localised vitrification and bloating in ceramic building material caused by a particle of combustible temper material
Fig. 7.6 Glazed ceramic building material
Fig. 7.7 Addition of straw to the paste of unfired clay wall covering
Fig. 7.8 Coarse textured unfired earthen construction material
Fig. 7.9 The crystals of gypsum in this sample of unfired construction material are suggestive of the use of clay from a nearby lake
Fig. 7.10 Coarse heterogeneous paste of unfired construction material
Fig. 7.11 Low refractory paste of unfired clay material used to build firing structure
Fig. 7.12 Elongate voids from plant temper within unfired clay material used to build firing structure
Fig. 7.13 Sandy inclusion-rich paste of unfired clay material used to build firing structure
Fig. 7.14 The clay matrix of this sample has vitrified due to exposure to sustained high temperature
Fig. 7.15 This sample of kiln furniture was manufactured from a fine clay paste thatmatches that of the pottery fired in the kiln
Fig. 7.16 Sand-tempered paste of kiln furniture
Fig. 7.17 This briquetage sample exhibits parallel sided voids that were formed by the destruction of plant temper that burned out during firing
Fig. 7.18 Refractory object with two compositionally different layers. A lining of fine clay has been added to the inside of the coarse sand-tempered vessel
Fig. 7.19 Sand tempered clay paste used for production of refractory ceramic
Fig. 7.20 Unused refractory ceramic revealing its original paste recipe
Fig. 7.21 Dark carbon-rich paste of used refractory ceramic
Fig. 7.22 Acicular crystals of mullite formed during the use of refractory ceramic vessel at high temperature
Fig. 7.23 Opaque graphite temper flakes added to refractory ceramic
Fig. 7.24 Crystalline slag residue left on used refractory vessel from smelting process
Fig. 7.25 Vesicular crystalline slag residue left on used refractory tool from smelting process
Fig. 7.26 Residue left on interior surface of refractory ceramic
Fig. 7.27 Fuel ash slag developed on the edge of refractory vessel during use at high temperature
Fig. 7.28 Clay casting core from bronze object
Fig. 7.29 Ceramic material from glass making core, prepared as a thin section
Fig. 7.30 Ceramic material of glass making core in thin section
Fig. 7.31 Stem of ceramic smoking implement seen in cross section
Fig. 7.32 The paste of this large multi-component ceramic sculpture was prepared by adding well-sorted, compositionally diverse sand temper to silty non-calcareous base clay
Fig. 7.33 Cementitious building material with visible aggregate, binder and pores
Fig. 7.34 Cementitious material attached to architectural ceramic
Fig. 7.35 Lime lump in cementitious building material
Fig. 7.36 Hydraulic reaction rims around pozzolanic additives in cementitious building material
Fig. 7.37 Quartzose sand added as aggregate to cementitious building material
Fig. 7.38 Calcareous sand added as aggregate to cementitious building material
Fig. 7.39 Fibre added as aggregate to cementitious building material
Fig. 7.40 Charcoal dust added as aggregate to cementitious building material
Fig. 7.41 Charcoal particle in cementitious building material
Fig. 7.42 Elongate shrinkage void formed during the recarbonation of the lime matrix of cementitious building material
Fig. 7.43 Gypsum crystals in cementitious building materials
Fig. 7.44 Microstratigraphy of cementitious building materials
Fig. 7.45 Cementitious building material composed of coarse aggregate particles derived from igneous and sedimentary rock
Fig. 7.46 Stoneware ceramic composed of a very fine, well-vitrified clay matrix that has low porosity
Fig. 7.47 Mullite crystals visible in stoneware at high magnification
Fig. 7.48 Porcelain in thin section with with very fine glassy body and transparent glaze layer
Fig. 7.49 Fritware/stonepaste ceramic artefact in thin section
Fig. 7.50 Faience in thin section
8: INSTRUMENTAL GEOCHEMISTRY OF ANCIENT CERAMICS
8.1 Introduction
8.2 The Chemical Composition of Ceramics
8.3 Equipment & Preparation
8.4 Quality Control
8.5 Descriptive Statistics
8.6 Choice of Elements
8.7 Normalisation, Standardisation & Transformation
8.8 Detecting Geochemical Patterning
8.9 Data Presentation
8.10 Reconciling Geochemical & Petrographic Data
8.11 Geochemical Provenance Determination
8.12 Geochemistry & Ceramic Technology
8.13 Further Reading
Figures (Chapter 8)
Fig. 8.1 The internal structure of an atom of the element silicon
Fig. 8.2 The Periodic Table of elements used to classify all naturally occurring and human-made elements
Fig. 8.3 The average geochemical composition of archaeological ceramics
Fig. 8.4 Nuclear reactor used for instrumental neutron activation analysis
Fig. 8.5 The principle of instrumental neutron activation analysis
Fig. 8.6 The principle of X-ray fluorescence spectroscopy (XRF)
Fig. 8.7 X-ray spectrum recorded on archaeological ceramic sample via energy dispersive X-ray fluourescence (ED-XRF)
Fig. 8.8 Comparison of spectral quality of energy dispersive (ED-XRF) and wavelength dispersive X-ray fuourescence (WD-XRF)
Fig. 8.9 Geochemical characterisation being undertaken non-destructively on highly valuable complete ceramics within a museum setting using portable XRF (pXRF)
Fig. 8.10 Simplified schematic diagram of an inductively coupled plasma mass spectrometer (ICP-MS)
Fig. 8.11 Sample preparation equipment for geochemical characterisation of archaeological ceramics
Fig. 8.12 Map of geographical coverage and numbers of archaeological ceramic samples from the USA analysed via INAA
Fig. 8.13 Certified reference materials (CRMs) or ‘standards’ for the calibration and quality control of geochemical analysis of archaeological ceramics
Fig. 8.14 Calibration curve between the measured (X-axis) and certified values (Y-axis) of Zr in a series of CRMs as recorded by pXRF
Fig. 8.15 Schematic diagram demonstrating the data quality concepts of accuracy and precision, using target practice as an analogy
Fig. 8.16 Geochemical data on 50 archaeological ceramic sherds
Fig. 8.17 Box-whisker plots of all trace elements from the dataset in Fig. 8.16
Fig. 8.18 Histograms of selected elements from the dataset in Fig. 8.16
Fig. 8.19 Variation matrix of the geochemical data in Fig. 8.29
Fig. 8.20 Bivariate scatterplots of selected pairs of elements from the dataset in Fig. 8.16
Fig. 8.21 Geochemical data recorded on 70 archaeological ceramic sherds via INAA, including analytical totals
Fig. 8.22 Element-to-stoichiometric oxide conversion factors for selected elements occuring in archaeological ceramics
Fig. 8.23 Dilution effect of change in a single major element on the abundance of all other elements in mock geochemical dataset
Fig. 8.24 The same mock dataset above, with SiO2 removed (upper table) and the datanormalised to the mean total (lower table).
Fig. 8.25 The geochemical data in Fig. 8.16 after standadisation
Fig. 8.26 The geochemical data in Fig. 8.16 after transformation to the base 10 logarithm
Fig. 8.27 Box-whisker plots of all trace elements from the dataset in Figs. 8.16 & 8.17 after transformation to base 10 logarithms
Fig. 8.28 Additive log ratio transformation (ALR) of the data in Fig. 8.29
Fig. 8.29 Spreadsheet of geochemical data coloured by the typology of the analysed sherds and sorted by the values for a single element (Co)
Fig. 8.30 The same data table as Fig. 8.29 above, but sorted by the element As
Fig. 8.31 Bivariate scatterplot of the concentration of Co versus Ca in the dataset inFigs. 8.29 & 8.30, labelled by the typology of the analysed sherds
Fig. 8.32 Geochemical data on 30 oxides and elements within 70 archaeological ceramic sherds
Fig. 8.33 Variance explained by principal components derived from PCA of dataset in Fig. 8.32, in tabular format and plotted as a ‘scree plot’
Fig. 8.34 Score plot for principal components 1 and 2 in Fig. 8.33 above, derived from PCA of the dataset in Fig. 8.32
Fig. 8.35 Component loading values for the variables (elements) in PCA of the dataset in Fig. 8.32 (left) and plot of the loadings for components 1 and 2 (right)
Fig. 8.36 Bivariate scatterplots of pairs of uncorrelated elements selected based on theloading plot in Fig. 8.35 above
Fig. 8.37 Score plots for components 1 and 3 (left - 55% variance explained) and 2 and 3 (right - 28% variance explained) derived from PCA of dataset in Fig. 8.32
Fig. 8.38 Three-dimensional score plot of components 1, 2 and 3 derived from PCA of dataset in Fig. 8.32, explaining 67% of the total variance
Fig. 8.39 Scatterplots of scores for components 1 and 2 derived from PCA of dataset in Fig. 8.32, with samples labelled by corresponding archaeological information
Fig. 8.40 Score plot of PCA on 59 ceramic sherds, with a concentration of samples in the upper right of the plot, as well as two possible outliers above this
Fig. 8.41 Assignment of ceramics to previously defined groups from the same region (SDI1, SDI2, IMP1A, IMP1B, IMP2), based on the abundance of La and Sc
Fig. 8.42 PCA scoreplot of full dataset with main group and outliers (left) and plot of the same PC scores for the main group only (right).
Fig. 8.43 Box plots of the dispersion of values for two discriminant elements of samples belonging to the four possible groups in the bivariate scatterplot
Fig. 8.44 HCA dendrogram of the geochemical dataset in Fig. 8.32 using Ward’s Method and squared euclidean distance, with samples labelled and coloured by fabric
Fig. 8.45 Dendrogram of HCA on dataset in Fig. 8.29, revealing several groups and one outlier, when split by the dashed line
Fig. 8.46 The same dataset as Fig. 8.45 above but clustered using Ward’s Method
Fig. 8.47 Comparison of PCA and HCA of the dataset in Fig. 8.32
Fig. 8.48 Linear discriminant analysis scatterplot comparing 11 clay samples (black dots) with three compositional groups (grey regions) detected by PCA within 59 sherds
Fig. 8.49 ‘Mixed Mode’ statistical exploration of geochemical and petrographic data on the same ceramic samples, via PCA
Fig. 8.50 Descriptive statistics of geochemical ‘control groups’ of ceramics determined by PCA
Fig. 8.51 PCA scoreplot and bivariate elemental scatterplot revealing a dispersed ‘cloud’, within which specific types of samples (in this case ceramics with different potter’s marks) can be discerned by labelling the samples
Fig. 8.52 Score plot in which the locations of specific samples have been highlighted by greying out others
Fig. 8.53 Ternary plot of the relative abundance of SiO2, Al2O3 and CaO in the ceramic dataset in Fig. 8.32
Fig. 8.54 Spiderplot of the abundance of trace elements in the dataset in Fig. 8.32
Fig. 8.55 Geochemical maps of the abundance of selected elements in the topsoil of England and Wales, indicating paterns related to the underlying geology
Fig. 8.56 PCA of sherds from a single site and clay samples from three lanscape zones
Fig. 8.57 Geographic distribution of geochemical groups at 14 sites, showing higher abundance of group A in the west, B and C in the east, and E in the north
Fig. 8.58 The outliers in this PCA score plot of geochemical data have distinct petrographic compositions that represent rare imported ceramics
Fig. 8.59 Linear discriminant analysis of the geochemical composition of samples from nine deposits of clay on Crete, Greece
Fig. 8.60 Establishment of geochemical reference groups of ceramics from five contemporaneous kiln sites by the analysis of 150 waster sherds
Fig. 8.61 Experiment demonstrating the effect of clay mixing and tempering on the major, minor and trace element composition of natural clay sources
Fig. 8.62 Effect of temper on a geochemical dataset of ceramics
9: SCANNING ELECTRON MICROSCOPY & X-RAY DIFFRACTION OF ANCIENT CERAMICS
9.1 Introduction
9.2 Scanning Electron Microscopy
9.3 SEM Geochemical Characterisation
9.4 SEM Mineralogical Characterisation
9.5 SEM versus Thin Section Petrography & Bulk Geochemistry
9.6 X-Ray Diffraction Analysis of Ceramics
9.7 Further Reading
Figures (Chapter 9)
Fig. 9.1 A modern scanning electron microscope with EDS capabilities
Fig. 9.2 The principle of scanning electron microscopy
Fig. 9.3 Archaeological ceramic sherd seen in fresh fracture in the SEM with SE imaging
Fig. 9.4 Simplified diagram of the main components of a basic scanning electron microscope
Fig. 9.5 Archaeological ceramic samples prepared for analysis in the SEM
Fig. 9.6 Vitrification microstructure of non-calcareous archaeological ceramic sherd seen in the SEM with SE imaging
Fig. 9.7 Vitrification microstructure of non-calcareous archaeological ceramic sherd seen in the SEM with SE imaging
Fig. 9.8 Fresh fracture of highly-fired archaeological ceramic sherd seen in the SEM with SE imaging
Fig. 9.9 Pennate diatom frustule (centre) seen in fresh fracture of archaeological ceramic sherd in the SEM with SE imaging
Fig. 9.10 Minute rod-shaped sponge spicules seen in fresh fracture of archaeological ceramic sherd in the SEM with SE imaging
Fig. 9.11 Polished resin-mounted cross section of archaeological ceramic sherd seen in the SEM with BSE imaging
Fig. 9.12 The same ceramic sherd as in Fig. 9.9 above, seen with SE imaging
Fig. 9.13 Polished cross section of ceramic refractory seen in the SEM with BSE imaging
Fig. 9.14 The same ceramic sherd as in Fig. 9.13 above, seen with SE imaging
Fig. 9.15 Feldspar inclusion with intergrowths seen in polished resin-mounted cross section of archaeological ceramic sherd in the SEM with BSE imaging
Fig. 9.16 SEM-EDS spectra and corresponding geochemical data collected from spot analyses of specific inclusions in polished resin-mounted cross section of the archaeological ceramic sherd in Fig. 9.11
Fig. 9.17 Geochemical composition of selected feldspar inclusions from the ceramic sample in Fig. 9.11, as determined by SEM-EDS.
Fig. 9.18 Geochemical characterisation of 15 volcanic glass inclusions in polished resin-mounted cross section of archaeological ceramic sherd using SEM-EDS spot analyses
Fig. 9.19 Comparison of the geochemical composition of argillaceous inclusions in the refractory sample in Fig. 9.13 with the surrounding fabric, via SEM-EDS area scans
Fig. 9.20 Geochemical comparison of slip layer and body in polished cross section of calcite tempered archaeological ceramic sherd using SEM-EDS area scans
Fig. 9.21 Geochemical composition of glaze layer on polished thin section of archaeological ceramic determined by SEM-EDS area scans, with example spectrum
Fig. 9.22 SEM-EDS line scan data collected across the body, slip and glaze of an archaeological sherd in polished thin section
Fig. 9.23 Secondary electron image of polished thin section of porcelain, revealing its hard vitrified microstructure
Fig. 9.24 BSE image of the specimen in Fig. 9.23 above, revealing compositional similarity between body and glaze
Fig. 9.25 Geochemical composition of the clay body of the refractory ceramic in Fig. 9.13 (black star), as determined by SEM-EDS
Fig. 9.26 Geochemical composition of binder material used for historic cementitious structure, as determined by SEM-EDS on a polished block
Fig. 9.27 Composite (top) and individual SEM colour maps (bottom) of decorated ceramic sample
Fig. 9.28 Back-scattered electron (BSE) image (top) and corresponding elemental colour maps (bottom)
Fig. 9.29 False colour image of interpreted mineralogical composition of polished resin-mounted cross section of archaeological ceramic sherd using SEM-EDS
Fig. 9.30 False colour image of interpreted mineralogical composition of polished resin-mounted cross section of archaeological ceramic sherd using SEM-EDS
Fig. 9.31 Screenshot and trace element data from LA-ICP-MS analysis of volcanic glass inclusions in polished resin-mounted cross section of archaeological ceramic sherd
Fig. 9.32 Bragg’s Law and the diffraction of X-rays by mineral crystals
Fig. 9.33 Interior of X-ray diffractometer
Fig. 9.34 X-ray diffractogram of ceramic sherd with identified minerals
Fig. 9.35 X-ray diffractogram of cementitious building material indicating the presence of the mineral bassanite (Bas) formed by the degradation of gypsum
Fig. 9.36 X-ray diffractogram of vitrified refractory ceramic revealing the presence of graphite (Gr), which was added as temper
Fig. 9.37 Bar diagram of the stability of minerals during the firing of ceramics in an oxidising atmosphere
Fig. 9.38 Bar diagram of the stability of minerals during the firing of ceramics in a reducing atmosphere
Fig. 9.39 X-ray diffractograms of two ceramic sherds from the same fabric fired at different temperatures under reducing conditions
Fig. 9.40 X-ray diffractograms of ceramic material fired at different temperatures in an oxidising atmosphere
ACKNOWLEDGEMENTS
INDEX