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XRF analysis of Augustan coins
Astrik Gorghinian *, Adolfo Esposito*, Marco Ferretti**, Fiorenzo Catalli***
Channeling 2012, Alghero 23-28 september 2012
Aureus Pergamum 19-18 BC 35724/3 – 7.58 g
*Istituto Nazionale Fisica Nucleare Laboratori Nazionali di Frascati
** Consiglio Nazionale delle Ricerche Istituto per le Tecnologie Applicate ai Beni Culturali
***
AUGUSTUS Caius Octavius Thurinus
XRF analyses of Augustan coins 2
First Roman Emperor 27 BC – 14 AD Monetary Refom 23-20 BC (Weights, changes, composition)
XRF analyses of Augustan coins 3
The collection
Provenance
Archaeological Museum of Florence
(Grand Ducal coin cabinet)
Former owner
Medici and Este families
477 coins dated between 36 BC & 12 AD
eagle mark in Ag from Este collection
Aureus Lugdunum 2 BC – 4 AD 35724/7 – 7.88 g
XRF analyses of Augustan coins 4
Nemausus
.
Roman Imperial Mints
XRF analyses of Augustan coins 5
XRF spectrometer
Unisantis XMF 104 Measurment Geometry
Microscope X-ray tube
Detector
X-ray filter
Targeting lasers
Polycapillary lens Sample
Sample stage
XRF analyses of Augustan coins 6
XRF features ELEMENTAL COMPOSITION SURFACE ANALYSIS (layer depth 10 to 50 mm) QUANTITATIVE (if surface significant of bulk)
NON DESTRUCTIVE RAPID
Elemental composition allows to
group objects / evaluate compositional differences / test authenticity
XRF analyses of Augustan coins 7
Experimental set up
X-ray Tube Anode Mo
HV = 50 kV
I = 100 mA
t = 200 s
Optics Kumakhov lens f = 50 mm
Detector Si-PIN Shaping time 20 ms Area = 7 mm2
Detection limits
Au matrix: Ag 0.03%, Cu 1%
Ag matrix: Cu, Zn, As 0.03%; Au, Pb, Bi 0.01%
Cu matrix: Fe 0.006%; Ni 0.03%; Ag, Sn, Sb 0.2%; Pb 0.08%
Au, Ag: General Results
Au
Aurei (46)
Gold Quinarii (4)
Au≈100% for 46 coins
Ag (15-19%) & Cu (4-6%)
for 4 coins
3 of them are suspect fakes
Ag
Ag>92% for 150 denarii
Ag<92% for 5 denarii
silver plated 10 coins
Cu≈98.5 % 1 coin fake
Minor elements distinguish mints
Quinarii and Denarii from Brundisium are different
XRF analyses of Augustan coins 8
Cu (AES): General Results
Cu-Zn (Aurichalcum-brass)
Zn<19.2%
Sn and Pb correlated <1%
Sestertii (30)
3 possible fakes
Dupondii (25)
Cu> 96% for 5 coins
Sn & Pb content > 1%
for 2 coins
Cu
Asses (152)
91%<Cu<98%
Sn or Pb, Sn & Pb contents >1% for 7 coins
Trace elements distinguish date of issue
Semisses (8): Cu-Zn alloy!!
Quadrantes (32)
Cu≈98%
XRF analyses of Augustan coins 9
Denarii: Au content
Lugdunum
High Au
Rome/Spain
Medium Au
Brundisium
Low Au
XRF analyses of Augustan coins 10
Denarius Brundisium/Roma 29-27 BC 35724/167 – 3.67 g
32-2
9aC -- --
29-2
7aC --
28-2
0aC -- --
21 a
C
20-1
9aC -- --
19 a
C -- --
19 a
C --
19-1
8 aC
-- --
18 a
C --
18-1
7/16
aC --
17aC
--
16aC
--
15-1
3aC -- --
13aC
12aC
--
11-1
0aC
8aC --
2aC
-4dC
-- ?
0
1
2
3
4
5
Au
%
date of issue
Denarius
Mints
Cyrenaica 31-30/29 a.C.
?
Brundisium
Ephesus
Emerita
Samos
Nord Peloponneso
Colonia Patricia
Roma
Caesaraugusta
Pergamum
Lugdunum
Denarii: Cu content
Lugdunum
Very low Cu
Rome/Spain
Medium Cu
Brundisium
Low Cu
XRF analyses of Augustan coins 11
prim
a 2
7aC
32-2
9aC -- --
29-2
7aC --
28-2
0aC -- --
21 a
C
20-1
9aC -- --
19 a
C -- --
19 a
C --
19-1
8 a
C -- --
18 a
C --
18-1
7/1
6 a
C --
17aC --
16aC --
15-1
3aC -- --
13aC --
12aC
11-1
0aC
8aC --
2aC
-4dC -- -- ?
0
1
2
3
4
5
6
7 Denarius
Mint
Cyrenaica s31-30/29 a.C.
?
Brundisium
Ephesus
Emerita
Samos
Nord Peloponneso
Colonia Patricia
Roma
Caesaraugusta
Pergamum
Lugdunum
Cu
%
date of issue
Denarius Brundisium/Roma 29-27 BC 35724/167 – 3.67 g
Denarii: Pb content
Lugdunum
Low Pb
Rome/Spain
High Pb
Brundisium
Very low Pb
XRF analyses of Augustan coins 12
Denarius Brundisium/Roma 29-27 BC 35724/167 – 3.67 g
prim
a 2
7aC
32-2
9aC -- --
29-2
7aC --
28-2
0aC -- --
21 a
C
20-1
9aC -- --
19 a
C -- --
19 a
C --
19-1
8 a
C -- --
18 a
C --
18-1
7/1
6 a
C --
17aC --
16aC --
15-1
3aC -- --
13aC --
12aC
11-1
0aC
8aC --
2aC
-4dC -- -- ?
0,0
0,2
0,4
0,6
0,8
1,0
1,2
1,4
Pb
%
date of issue
Denarius
Mint
Cyrenaica 31-30/29 a.C.
?
Brundisium
Ephesus
Emerita
Samos
Nord Peloponneso
Colonia Patricia
Roma
Caesaraugusta
Pergamum
Lugdunum
Quinarii
quinarii struck in Brundisium
Are different
from denarii struck
in the same mint!!
XRF analyses of Augustan coins 13
0,00 0,25 0,50 0,75 1,00
0,00
0,25
0,50
0,75
1,00 0,0
0,2
0,4
0,6
0,8
1,0
Denari- Brundisium/Roma 32-29 a.C.
Denari- Brundisium/Roma 29-27 a.C.
Quinari- Brundisium/Roma 29-26 a.C.
Quinari- Emerita 25-23 a.C.
Quinari- Nord Peloponneso 21 a.C.
Pb %Au %
Cu %
Quinarius= 1/2 denarius Brundisium/Roma 29-26 BC 35724/207, 1.55 g
Sestertii
2.6%<Zn<19.2% - Zn distribution increases by time – Sn and Pb correlated
XRF analyses of Augustan coins 14
Sestertius Rome, C. Asinius Gallus
16 BC 35724/235 – 25.80 g
18aC -- 17aC -- -- 16aC -- -- 15aC -- 8dC -- 10dC
0
2
4
6
8
10
12
14
16
18
20
Zn
%
date of issue
Sestertius
Ephesus
Roma
Lugdunum
0,1 1
0,1
1
detection
limit
35691/9
35724/43635724/447
reproduction?
Pb
%
Sn %
Sestertius
Ephesus 25 a.C.
Roma 18 a.C.
Roma 17 a.C.
Roma 16 a.C.
Roma 15 a.C.
Lugdunum 8 d.C.
Lugdunum 10 d.C.
Dupondii
5 coins (over 25) are made of Cu> 96%
2 coins have Sn and Pb content > 1%
one of these (35724/333)
has Sn and Pb contents
near to the fake sestertii
XRF analyses of Augustan coins 15
Dupondius = 1/2 Sestertius
Lugdunum 10 AD 35724/256 – 10.70 g
0,1 1
0,1
1
detection limit
35724/417
35724/333
Pb
%
Sn %
Sestertius
Dupondius
Roma 18 a.C.
Roma 17 a.C.
Roma 16 a.C.
Roma 15 a.C.
Roma 7 a.C.
Lugdunum 8 d.C.
Lugdunum 10 d.C.
XRF analyses of Augustan coins 16
Ni, Ag, Sb are more abundant in 7 BC production
As Rome, C. Cassius
Celer
16 BC 35724/335 – 10.28g
ASSES
20-1
0aC
16aC
16aC
15aC --
15aC --
7aC --
7aC --
7aC --
6aC
8dC
10-1
4dC
11-1
2dC
0,2
0,4
0,6
0,8
1,0
Ni %
date of issue
As
Mint
Narbo B.C. 36(?)-35
Ephesus B.C. 25
Nemausus
Roma
Lugdunum
20-1
0aC
16aC
16aC
15aC --
15aC --
7aC --
7aC --
7aC --
6aC
8dC
10-1
4dC
11-1
2dC
0,0
0,2
0,4
0,6
0,8
1,0
1,2
1,4
1,6
1,8
Detection
Limit
Ag
%
date of issue
As
Mint
Narbo B.C. 36(?)-35
Ephesus B.C. 25
Nemausus
Roma
Lugdunum
20-1
0aC
16aC
16aC
15aC --
15aC --
7aC --
7aC --
7aC --
6aC
8dC
10-1
4dC
11-1
2dC
0,0
0,2
0,4
0,6
0,8
1,0
1,2
1,4
1,6
1,8
Detection
Limit
Sb
%
date of issue
As
Mint
Narbo B.C. 36(?)-35
Ephesus B.C. 25
Nemausus
Roma
Lugdunum
XRF analyses of Augustan coins 17
Ag - Ni are slightly correlated Ag - Sb are correlated
From Pb isotopes analysis Copper supply: mainly Sardigna and South Spain occasionaly Tuscany S. Klein Y. Lahaye G.P. Brey, The early roman imperial AES coniage II: tracing the copper sources by analysis of lead and copper isotopes-copper coins of Augustus and Tiberius, Archeaometry 46, 3 (2004) 469-480
ASSES
0,0 0,2 0,4 0,6 0,8 1,0 1,2 1,4 1,6
0,0
0,2
0,4
0,6
0,8
1,0
1,2
Detection
Limit
Ni%
Ag%
As
Narbo 36 a.C.
Nemausus 20-10 a.C. Nemausus 10-14 d.C.
Roma AG Roma CC Roma GL 16 a.C.
Roma NS Roma P Roma PR 15 a.C.
Roma LA Roma MT Roma SO 7 a.C.
Roma LN Roma NQ Roma VVM 6 a.C.
Roma 11-12 a.C.
Lugdunum 8 d.C. Lugdunum 10 d.C.
0,0 0,2 0,4 0,6 0,8 1,0 1,2 1,4 1,6
0,0
0,2
0,4
0,6
0,8
1,0
1,2
1,4
1,6
1,8
2,0
Detection
Limit
Detection
Limit
Sb
%
Ag %
As
Narbo 36 a.C.
Nemausus 20-10 a.C. Nemausus 10-14 d.C.
Ephesus
Roma AG Roma CC Roma GL 16 a.C.
Roma NS Roma P Roma PR 15 a.C.
Roma LA Roma MT Roma SO 7 a.C.
Roma LN Roma NQ Roma VVM 6 a.C.
Roma 11-12 d.C.
Lugdunum 8 d.C. Lugdunum 10 d.C.
Semisses
Little statistics (8 coins)
Semisses are made of Cu-Zn alloy, similar to sestertii and dupondii (not pure Cu as request)
The only semis by Philippi is completely different from alll the aes coins (Zn 0.3%, Sn 7.5%, Pb 3.4% : it’s a bronze)
XRF analyses of Augustan coins 18
Semis =1/2 as
Lugdunum 8 AD 35702/23 - 4.66g
Quadrantes
Quadrantes are mainly composed by Cu≈98%
(Sn < detection limit, Ag and Sb are around the detection limit, Pb<0.6%)
XRF analyses of Augustan coins 19
Quadrans= 1/4 as Roma, Lamia Silius Annius
9 BC 35724/366, 3.03 g
14%<Zn<18% for 3 coins minted at Lugdunum (one suspected fake) Note: except 2 coins from Lugdunum all the analyzed qadrantes are minted after 9 BC
Quadrans Lugdunum 10 AD 35724/446, 3.04 g
Modern reproduction
AES (base metal) Comparison
Sestertii/Dupondii
Pb & Sn: present
Sb: absent
Ag: present in dupondii,
absent in sestertii
Asses/Quadrantes
Pb & Sn: almost absent
Sb: present (asses 16-15
BC, some quadrantes)
Ag: present (<asses 16-
15 BC, quadrantes 4-5 BC)
XRF analyses of Augustan coins 20
XRF analyses of Augustan coins 21
Conclusion:
Cu coins contain Sb
Cu-Zn coins contain Sn & Pb
AES
36-3
5aC --
25aC --
20-1
0aC --
18aC --
17aC --
16aC --
15aC --
15-1
0aC
9aC
8aC
7aC --
6aC
5aC
4aC
8dC
8dC -- --
10dC
10dC
10dC
10-1
4dC
11-1
2dC
0,0
0,4
0,8
1,2
1,6
2,0
2,4
2,8
3,2
3,6
4,0
4,4
4,8
5,2
5,6
6,0
Detection
Limit
Sn
%
date of issue
As
Narbo
Ephesus
Nemusus
Roma
Lugdunum
Quadrans
Lugdunum
Roma
Sestertius
Ephesus
Roma
Lugdunum
Dupondius
Roma
Lugdunum
Semis
Lugdunum
36-3
5aC --
25aC --
20-1
0aC --
18aC --
17aC --
16aC --
15aC --
15-1
0aC
9aC
8aC
7aC --
6aC
5aC
4aC
8dC
8dC -- --
10dC
10dC
10dC
10-1
4dC
11-1
2dC
0,0
0,4
0,8
1,2
1,6
2,0
Detection
Limit
Sb %
date of issue
As
Narbo
Ephesus
Nemusus
Roma
Lugdunum
Quadrans
Lugdunum
Roma
Sestertius
Ephesus
Roma
Lugdunum
Dupondius
Roma
Lugdunum
Semis
Lugdunum
36-3
5aC --
25aC --
20-1
0aC --
18aC --
17aC --
16aC --
15aC --
15-1
0aC
9aC
8aC
7aC --
6aC
5aC
4aC
8dC
8dC -- --
10dC
10dC
10dC
10-1
4dC
11-1
2dC
0,0
0,2
0,4
0,6
0,8
1,0
1,2
1,4
1,6
1,8
Detection
Limit
Ag
%
date of issue
As
Narbo
Ephesus
Nemusus
Roma
Lugdunum
Quadranti
Lugdunum
Roma
Sesterzi
Ephesus
Roma
Lugdunum
Dupondi
Roma
Lugdunum
Semissi
Lugdunum
Thanks for your Attention
XRF analyses of Augustan coins 22
Augustus, Pontifex Maximus After B.C. 12
Museo Nazionale Romano Palazzo Massimo Rome
Mint provenance
Aurei (50) - Lugdunum 50%, Colonia Patricia 17%, Brundisium,
13%, Rome 7%, other 13%
Denarii (166) – Rome 24%, Lugdunum 23%, Colonia Patricia 20%,
Brundisium 15%, other 18%;
Quinari (16) – Brundisium 88%
Sextertii (30) – Rome 77%, Lugdunum 23%, other 3%
Dupondii (25) – Rome 72%, Lugdunum 28%
Semisses (8) - Lugdunum 7 coins, Philippi 1 coin
Asses (152) – Rome 88.7%, Lugdunum 5.3%, other 6%
Quadrantes (32) – Rome 91%, Lugdunum 9%
XRF analyses of Augustan coins 23
XRF analyses of Augustan coins 24
The Augustan Reform B.C. 23 – B.C. 20
aur quin Au
denar quin Ag
sester dupon as sem quad
aureus 7,79 g 2 25 50 100 200 400 800 1600
quinarius 3,89g 12,5 25 50 100 200 400 800
denarius 3,89g 2 4 8 16 32 64
quinarius 1,94 g 2 4 8 16 32
sestertius 27,28g 2 4 8 16
dupondius 13,64 g 2 4 8
as 10,91 g 2 4
semis 5,20 g 2
quadrans 1,70 g
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