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Secrets of the Anglo-Saxon Goldsmith:
The results from the analysis of the gold in the Staffordshire Hoard
Dr Eleanor Blakelock
Staffordshire Hoard
• Found in 2009 by a metal detectorist
• Near the village of Hammerwich, near
Lichfield, in Staffordshire.
• Excavation by archaeologists from
Staffordshire County Council, and a team
from Birmingham Archaeology, which was
funded by English Heritage.
• When the discovery was publicly announced,
it attracted worldwide attention with people
queuing for hours to see the hoard.
Staffordshire Hoard
• Over 3,500 objects or object fragments have
been found, predominately gold or silver.
• The Hoard is essentially military in character.
The bulk of the identified pieces comes from
the handles of edged weapons, shield fittings
and one or more helmets.
Anglo-Saxon Warrior Elite
“The great Anglo-Saxon poem Beowulf, once
believed to be artistic exaggeration, now has a
true mirror in archaeology.”
Chris Fern
Staffordshire Hoard
Staffordshire Hoard
But ……… there are a few other objects of unknown use
And a small number of explicitly Christian items have also
been identified
It is still likely that these were taken from a battlefield, as
it was not uncommon to take your priest to war
Staffordshire Hoard
• The Hoard was valued at £3.285 million
• An international fundraising campaign to save the hoard for the nation was mounted
• In less than 10 weeks it was a success
• It is now jointly owned by Birmingham and Stoke-on-Trent City councils.
• The collection is displayed in four museums
Staffordshire Hoard
Research Project
• Metals analysis just one part of a larger study ....Contextualising Metal Detected Discoveries:
Staffordshire Anglo-Saxon Hoard
Conservation
Reconstruction
Reconstruction
Typology
• Chris Fern the archaeologist is trying to create a typology to date the Hoard using stylistic information
• Also looking at status of individuals
Typology
c.620AD
c.625AD
c. 610AD
c. 560AD
c. 630ADc. 600AD
Identifying objects
Mystery Object
• No idea what it is, no parallels anywhere
• Is it the lid of a container?
• Saddle fitting?
• Or an extension to a hat?
Identifying objects
• This is a manuscript showing the prophet Ezra and he is wearing something on his head
Analysis• Gold
• Silver
• Copper alloys
• Gilding
• Garnet
• Glass
• Niello inlay
• Green inlay
• Organic
Research Project
• Metals analysis just one part of a larger study ....Contextualising Metal Detected Discoveries:
Staffordshire Anglo-Saxon Hoard
– Conservation & public engagement– Typology and classification of objects– Scientific analysis of materials
• Gold & silver• Organics• Pastes and glass
– Fully illustrated publication– Online research database
Gold Research Project
• Provenance the gold
• Can the gold be used to date the hoard
• Identifying workshops
• Choice of alloy for specific roles
• Effects of burial environment on gold
Gold Research Project
158 objects analysed
o 114 Staffordshire Hoard
o 1 Stoke on Trent
o 43 British Museum
• During the analysis 288 different components were analysed
o Sheets
o Filigree panels
o Cast or solid
o Wires
o Cell walls
o Large borders
o Caps
Gold Research Project
Choice of instrument
XRF
• Cheap and quick
• Museum owned one
• Completely non-destructive
• Large beam size
• Relatively deep penetration
SEM-EDX
• Small beam size
• Limited by object size
• Small penetration so surface had to be prepared
Core
Surface
Core
Surface
Anglo-Saxon gold
• Gold in the past was not pure
– Native gold contains silver and some copper
• Deliberate alloying of gold was also used to change the properties of gold
– Working properties
– Melting temperatures
– Colour
Anglo-Saxon gold100% gold
more silver
90% gold 10% silver
80% gold 20% silver
more copper
• This graph shows the range of gold alloys in the Staffordshire Hoard objects analysed
• Majority of objects have between 1-4% copper
70% gold 30% silver
Anglo-Saxon gold
• During the Saxon period there was a gold shortage
• Studies of coinage has shown a general change in the gold to silver ratios
• It was hoped that this information could be used to date the Staffordshire Hoard objects
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70.0
80.0
90.0
100.0
0.0 20.0 40.0 60.0 80.0 100.0Si
lver
Wt%
Gold Wt%
c.630-640
c.630-660
c.650-675
c.670-680
Silver increases over time
Anglo-Saxon gold
• No clear pattern was seen relating to dates
• The Hoard will have to be dated based on stylistic differences
Anglo-Saxon gold
• Are there regional differences to perhaps indicate workshops?
• The analysis showed no clear regional groups
• Exception was Suffolk
Anglo-Saxon gold
• There was no obvious link between function and alloy either
Anglo-Saxon gold
• Evidence points to recycling and mixing
0
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40 60 80 100
Wei
ght%
Ag
Weight% Au
0
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20
30
40
50
60
0 2 4 6
Wei
ght%
Ag
Weight% Cu
Surface Enrichment Project
• Gold is resistant to corrosion but ..
.....the surface can be depleted of base elements, either naturally or deliberately
• In the burial environment
– Copper is depleted
– Small quantities of silver could also be potentially lost
Small quantities of silver lost at surface
Gold core composition K1143
83.7% gold, 14.3% silver and 2% copper
85.3% gold, 13.6% silver and 1.1% copper
Copper lost at surface
Gold enriched surface
Surface Enrichment Project
• The term ‘surface enrichment’ is used but the surface has technically not been enriched in gold
• A pilot study was carried out on 16 objects to investigate the effects of the burial environment
Small quantities of silver lost at surface
Gold core composition K1143
83.7% gold, 14.3% silver and 2% copper
85.3% gold, 13.6% silver and 1.1% copper
Copper lost at surface
Gold enriched surface
Surface Enrichment Project
• Surface enrichment due to burial
• Hilt-plate K1143
• A small loss of silver at the surface.
• A substantial loss of copper due to the burial environment
10
11
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13
14
15
16
75 80 85 90
Wei
ght
% A
g
Weight % Au
Surface
Sub-surface
10
11
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13
14
15
16
0 1 2 3
Wei
ght
% A
g
Weight % Cu
surface
subsurface
Surface Enrichment Project
Copper lost at surface Silver lost at surface
Gold core composition K1221
Gold enriched surface
70% gold, 28% silver and 2% copper
84% gold, 15% silver and 1% copper
• Surface enrichment seen during pilot study
– A large number of objects had a significant loss of silver at the surface
– Some objects had over 40% depletion of silver
– Could not be explained by natural mechanisms
Surface Enrichment Project
Sub-surface Surface
Sub-surface
Surface
0
5
10
15
20
25
30
35
60 70 80 90
Wei
ght
% A
g
Weight % Au
Surface
Sub-surface
0
5
10
15
20
25
30
35
0 1 2 3 4
Wei
ght
% A
g
Weight % Cu
• Surface enrichment seen during pilot study
Surface Enrichment Project
The importance of the pilot study was recognised, so the surface enrichment project was extended.
This aimed to investigate differences in enrichment between
• Time periods
• Find location
• Components, to learn more about object construction and goldsmith workshops
• Function (including Male vs Female objects)
Surface Enrichment Project
• The results suggested that only specific components on each object were being enriched
-60%
-40%
-20%
0%
20%
40%
60%
80%
-30% -20% -10% 0% 10% 20%
% lo
ss/g
ain
of
Ag
% loss/gain of Au
Backing sheet
Wire
Cap
Cell Wall
All the components appear to have a similar core composition
Surface Enrichment Case study - K88
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45.0
40.0 50.0 60.0 70.0 80.0
Wei
ght
% A
g
Weight % Au
Base sheet sub-surface
Top of cap sub-surface
Large filigree wire on panel sub-surface
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Wei
ght
% A
g
Weight % Cu
All the components appear to have a similar core composition
Analysis showed that the sheet was depleted in silver
Surface Enrichment Case study - K88
Sub-surface
Surface
Sub-surface Surface
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35.0
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Wei
ght
% A
g
Weight % Au
Base sheet surface
Base sheet sub-surface
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30.0
40.0
50.0
0.0 1.0 2.0 3.0 4.0 5.0
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ght
% A
g
Weight % Cu
Sub-surface Surface
All the components appear to have a similar core composition
Analysis showed that the sheet was depleted in silver
But the cap and wires show no sign of deliberate treatment
Surface Enrichment Case study - K88
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ght
% A
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Weight % Au
Base sheet surfaceBase sheet sub-surfaceTop of cap surfaceTop of cap sub-surfaceLarge filigree wire on panel surfaceLarge filigree wire on panel sub-surface
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We
igh
t %
Ag
Weight % Cu
Sub-surface Surface
Sub-surface
Surface
Surface Enrichment Case study - K88
This may explain the colour contrast often seen between wires and the sheets behind them
It also suggests that the treatment was most likely taking place in the workshop
Surface Enrichment Project
• Analysis was undertaken on sheets from different types of decorated object
o Filigree
o Cloisonné
o Cloisonné and filigree
o Green cloisonné
o Niello
o As cast or engraved objects
Surface Enrichment Project
• The level of enrichment is different, based on the decoration method
• Sheets are more often enriched
obehind filigree
oengraved designs or plain sheets
• This suggests a deliberate choice by the goldsmith
Surface Enrichment Project
• No difference in type or amount of enrichment based on object
– Date
– Location
– Function
the exception being ...
Male vs Female items -50%
-40%
-30%
-20%
-10%
0%
10%
20%
30%
40%
50%
-100% -50% 0% 50% 100%
Ag
wei
ght%
Au weight%
Sword fitting
Coin
Items of personal adornment (female)
Items of personal adornment (male)
Mount
Religious function
-50%
-40%
-30%
-20%
-10%
0%
10%
20%
30%
40%
50%
-100% -80% -60% -40% -20% 0% 20% 40% 60% 80% 100%
Au
En
rich
men
t Fa
cto
r %
Ag Enrichment Factor %
c. AD520-550
c. AD580-610
c. AD600-630
c. AD620-660
-50%
-40%
-30%
-20%
-10%
0%
10%
20%
30%
40%
50%
-100% -50% 0% 50% 100%
Au
En
rich
men
t Fa
cto
r %
Ag Enrichment Factor %
Staffordshire
Cumberland
Buckinghamshire
Kent
Lincolnshire
Norfolk
North Yorkshire
Northamptonshire
Suffolk
Surface Enrichment Project
• Part of the reason for including the British Museum collection was to get representative female items
Female vsMale
Surface Enrichment Project
• More of the male associated items tend to have a higher gold core
• Instead the female items are more often enriched than male items
• This means that they tend to have the same surface compositions
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Ag
Wt%
Au Wt%
Decorative item (female)
Decorative item (male)
-0.80
-0.60
-0.40
-0.20
0.00
0.20
0.40
0.60
0.80
1.00
-0.40 -0.30 -0.20 -0.10 0.00 0.10
% lo
ss/g
ain
of
Ag
% loss/gain of Au
0.0
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Wt%
Au Wt%
Surface
Sub-surface
New Research at Birmingham
• Carried out in conjunction with Birmingham University
• SEM-EDX and metallographic analysis of a small number of objects
• Aim to determine
– the type of solders used
– how the surface was enriched
Solder
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80.0
01.
5 34.
5 67.
5 910
.5 1213
.5 1516
.5 1819
.5 2122
.5 2425
.5 2728
.5 3031
.5 3334
.5 3637
.5 3940
.5 4243
.5 4546
.5 4849
.5 5152
.5 5455
.5 5758
.5 6061
.5
Cu
Ag
Au
Solder
‘1 ounce of copper calcine, 3 solidus of olive-oil soap, 1 solidus of calcothar. For use mix these together first grinding the copper calcine and the calcothar separately into powder. Mix with as
much soap and water as is necessary for gold solder.’Mappae Clavicula circa 9th century AD Italy
So how did the Goldsmiths do it?Historical Sources Liquid or cementation bath Other
Kauṭilῑya Arthaśāstra Coat sample with Indus soil and heated
Agatharchides’s ‘On the Erythraean Sea’Lead, salt and tin, added to barley bran and placed in
vessel, heated
Pliny the Elder ‘Natural History’Gold heated with twice weight salt and three times
copper pyrites within earthenware jar
Leyden (or Leiden) Papyri
• Cementation of gold using misy, alum, salt coat gold
sheets but this is for purification as the gold is
melted
• Coloration of gold using misy, salt and vinegar in a
vessel which is heated
• 1 part gold and 2 parts lead powdered, coat and
heat object (for gilding copper objects)
• Yellow natron and salt, rubbed to gild
• Missy, alum and celandine in urine used to coat
sample heat applied to colour gold
Codex Lucensis 490Tragacanth, salt and vinegar used on gold textile
threads
Late Longobardian Latin document at
LuccaDragant and vinegar to colour gold threads
Mappae Clavicula
• Sinopia 1 part and 2 parts salt coat sheet and seal
with potters clay
• Paste of vitriol and salt, coat gold with it and heat
Greek manuscript ‘ On the noble and
illustrious art of the goldsmith’
• Salt, tartar dregs, third brick dust place in crucible
with gold, but this is for purification as the gold is
melted
• Suphur, garlic, urine and salt place sheet into
mixture
Oche and salt-ammoniac mixture to give golden
colour
Theophilus ‘ On Divers Arts’Salt, clay, urine in vessel with gold and heated, but this
is for purification as the gold is meltedSpanish gold with basilisk powder
Agricola ‘De Re Metallica’ Many recipes for the parting of gold by cementation
Benvenuto Cellini ‘Goldsmithing and
sculpture’Royal cement using tartar and brick dust to purify
Salt-petre, vitriol, salt and verdigris recipe applied
over the surface with a feather to colour gold
Vannoccio Biringuccio ‘treatise on metals
and metallurgy’Salt, brick dust with or without vitriol
• Verdigris and salt rubbed and heated
• Washed in boiled powdered yellow sulphur
BC
Ro
man
Co
nte
mp
ora
ryN
orm
anM
ed
ieva
l
So how did the Goldsmiths do it?
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0
1.5 3
4.5 6
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19.5 21
22.5 24
25.5 27
28.5 30
31.5
Cu
Ag
Au
So how did the Goldsmiths do it?Historical Sources Liquid or cementation bath Other
Kauṭilῑya Arthaśāstra Coat sample with Indus soil and heated
Agatharchides’s ‘On the Erythraean Sea’Lead, salt and tin, added to barley bran and placed in
vessel, heated
Pliny the Elder ‘Natural History’Gold heated with twice weight salt and three times
copper pyrites within earthenware jar
Leyden (or Leiden) Papyri
• Cementation of gold using misy, alum, salt coat gold
sheets but this is for purification as the gold is
melted
• Coloration of gold using misy, salt and vinegar in a
vessel which is heated
• 1 part gold and 2 parts lead powdered, coat and
heat object (for gilding copper objects)
• Yellow natron and salt, rubbed to gild
• Missy, alum and celandine in urine used to coat
sample heat applied to colour gold
Codex Lucensis 490Tragacanth, salt and vinegar used on gold textile
threads
Late Longobardian Latin document at
LuccaDragant and vinegar to colour gold threads
Mappae Clavicula
• Sinopia 1 part and 2 parts salt coat sheet and seal
with potters clay
• Paste of vitriol and salt, coat gold with it and heat
Greek manuscript ‘ On the noble and
illustrious art of the goldsmith’
• Salt, tartar dregs, third brick dust place in crucible
with gold, but this is for purification as the gold is
melted
• Suphur, garlic, urine and salt place sheet into
mixture
Oche and salt-ammoniac mixture to give golden
colour
Theophilus ‘ On Divers Arts’Salt, clay, urine in vessel with gold and heated, but this
is for purification as the gold is meltedSpanish gold with basilisk powder
Agricola ‘De Re Metallica’ Many recipes for the parting of gold by cementation
Benvenuto Cellini ‘Goldsmithing and
sculpture’Royal cement using tartar and brick dust to purify
Salt-petre, vitriol, salt and verdigris recipe applied
over the surface with a feather to colour gold
Vannoccio Biringuccio ‘treatise on metals
and metallurgy’Salt, brick dust with or without vitriol
• Verdigris and salt rubbed and heated
• Washed in boiled powdered yellow sulphur
BC
Ro
man
Co
nte
mp
ora
ryN
orm
anM
ed
ieva
l
So how did the Goldsmiths do it?
0.0
10.0
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30.0
40.0
50.0
60.0
70.0
80.0
90.0
100.0
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57 59 61 63 65 67 69 71 73 75
Cu
Ag
Au
0
0.5
1
1.5
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57 59 61 63 65 67 69 71 73 75
Sulphur
So how did the Goldsmiths do it?Historical Sources Liquid or cementation bath Other
Kauṭilῑya Arthaśāstra Coat sample with Indus soil and heated
Agatharchides’s ‘On the Erythraean Sea’Lead, salt and tin, added to barley bran and placed in
vessel, heated
Pliny the Elder ‘Natural History’Gold heated with twice weight salt and three times
copper pyrites within earthenware jar
Leyden (or Leiden) Papyri
• Cementation of gold using misy, alum, salt coat gold
sheets but this is for purification as the gold is
melted
• Coloration of gold using misy, salt and vinegar in a
vessel which is heated
• 1 part gold and 2 parts lead powdered, coat and
heat object (for gilding copper objects)
• Yellow natron and salt, rubbed to gild
• Missy, alum and celandine in urine used to coat
sample heat applied to colour gold
Codex Lucensis 490Tragacanth, salt and vinegar used on gold textile
threads
Late Longobardian Latin document at
LuccaDragant and vinegar to colour gold threads
Mappae Clavicula
• Sinopia 1 part and 2 parts salt coat sheet and seal
with potters clay P
• Paste of vitriol and salt, coat gold with it and heat
Greek manuscript ‘ On the noble and
illustrious art of the goldsmith’
• Salt, tartar dregs, third brick dust place in crucible
with gold, but this is for purification as the gold is
melted
• Suphur, garlic, urine and salt place sheet into
mixture
Oche and salt-ammoniac mixture to give golden
colour
Theophilus ‘ On Divers Arts’Salt, clay, urine in vessel with gold and heated, but this
is for purification as the gold is meltedSpanish gold with basilisk powder
Agricola ‘De Re Metallica’ Many recipes for the parting of gold by cementation
Benvenuto Cellini ‘Goldsmithing and
sculpture’Royal cement using tartar and brick dust to purify
Salt-petre, vitriol, salt and verdigris recipe applied
over the surface with a feather to colour gold
Vannoccio Biringuccio ‘treatise on metals
and metallurgy’Salt, brick dust with or without vitriol
• Verdigris and salt rubbed and heated
• Washed in boiled powdered yellow sulphur
BC
Ro
man
Co
nte
mp
ora
ryN
orm
anM
ed
ieva
l
So how did the Goldsmiths do it?
• Leyden Papyrus ‘roasted misy, 3 parts; lamellose alum, (and) celandine, about 1
part; grind to the consistency of honey with the urine of a small child and colour the object; heat and immerse in cold water.’
‘For gilding a vase of silver or copper without leaves [of gold], dissolve some yellow natron and some salt in water, rub it with this and it will be gilded.’
• Codex Lucensis ‘take clean tragacanth and carefully pound it in a mortar and
salt in equal weights, and rub, mix with diluted vinegar, spread over the petals on both sides equally with the first; and heat on the hearth to a moderate degree.’
• Mappae Clavicula ‘Take vitriol and roast it, as you know how, and as much salt
again, and temper it with red wine not too thinly, in a copper pot, and coat the gold with it.’
Life of an object
• There are many pieces in the hoard that look like they belong as sets
• Therefore a couple of obvious sets were examined during this study
• This revealed more about their life history
Market Rasen Staffordshire Hoard
Seax set
Au Ag Cu
72.4 25.3 2.2
85.0 13.9 1.1
82.2 15.2 2.6
82.0 15.3 2.6
82.2 15.5 2.3
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
65.0 70.0 75.0 80.0 85.0 90.0
Wei
ght
% A
g
Weight % Au
K376 sub-surface
K354 sub-surface
K690 sub-surface
K370 sub-surface
K449 sub-surface
• The hilt collars all shared a similar core composition
• But the pommel cap has a different composition
• This suggests that the pommel was constructed at a different time to the rest of the set
Market Rasen set
• The sheet of the pommel is made from a similar alloy as the cap, but has been treated
8
9
10
11
12
13
14
15
84 85 86 87 88 89 90
Ag
Wt%
Au Wt%
Pommel sheet surface
Pommel sheet sub-surface
Pommel cap surface
Pommel cap sub-surface
Market Rasen set
• The sheets used in the pommel and both hilt collars are a similar composition
• The hilt plates however have different compositions
Au Ag Cu
85.3 12.8 1.9
75.2 21.6 3.2
83.6 13.8 2.7
84.7 13.4 1.9
77.2 20.4 2.4
Market Rasen set
• The bottom hilt plate has been treated to achieve a similar surface composition
• The top hilt plate hasn’t and is therefore a different colour
8
10
12
14
16
18
20
22
24
70 75 80 85 90
Ag
Wt%
Weight % Au
Pommel sheet surfacePommel sheet sub-surfaceTop hilt plate surfaceTop hilt plate sub-surfaceTop collar surfaceTop collar sub-surfaceBottom collar surfaceBottom collar sub-surfaceBottom hilt plate surfaceBottom hilt plate sub-surface
Conclusion
• We know very little about the Anglo-Saxon goldsmith who made these pieces
• Deliberate surface treatment in the Anglo-Saxon period
• The data is beginning to reveal the
• methods and techniques used by the goldsmiths
• some of the thought processes and decisions made by the goldsmiths
For access to equipment
For funding the research
And the thousands of members of the public who donated towards the acquisition of the Staffordshire Hoard and who continue to support this campaign.
Was English Heritage
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form for exchange of information and research in
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