the artists:the chemists: rebecca careyamber klein melissa coffershawn leary rick hamiltonrandall...
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The Artists: The Chemists:Rebecca Carey Amber KleinMelissa Coffer Shawn LearyRick Hamilton Randall Short
The Chemical Pigment Analysis of Samples
Removed from the Medieval Sculpture of the
Male Saint
Patricia Lang
Department of Chemistry, Ball State University
What gives rise to color in a molecule ?
What sorts of artists’ pigments
were used in ancient and medieval
times?
How can we
determine molecular
identity?
How is the scientific method applied to a real-world
problem?
The Course: Chemistry of Artists Pigments
Teleconferences with experts:
Dr. Mary Virginia OrnaDr. Beth Price
Other special course activities:• Made a modern synthetic pigment, Prussian Blue, and an egg tempera paint
• Sampling paints from the statue, microscopic examination of paints, collecting spectral data on the samples, and analyzing the spectra
• Trip to analytical laboratory in Noblesville to perform additional analysis
• Oral presentation to Peter Blume and Dr. Orna
• Collaborated on a written report
What? identify pigments & other artist materials
Why?(1) characterize artist & work(2) to determine if pigments
consistent with the date(3) chronology of paint application(4) conservation
Chemistry and Art
Circle of Hans MultscherGerman1400-1467Typical to be painted
Male Saint
Kreuztragender Christus-Created by Multscher in
1450
What do you think?
ToolsTechniquePigments
How do you create a wooden
sculpture?
Sample Collection
A team
effort!
Sample Locations
Sample 1
Sample 2
Sample 3
Sample 4
Sample 5
Sample 6
Sample 7
individual pigments, layering, texture, optical properties
physical separation according to color sometimes possible
Sampling approach
Origin of IR Spectroscopy
How?
3400 3300 1650
cm-1
ATR spectroscopy uses the phenomenon of total internal reflection.
Infrared Spectroscopy
Molecular Analysis
Energy Dispersive X-ray ANALYSIS
K Electron energy level
L Electron energy level
M Electron energy level
K α Kβ
eV2.0 4.0
Elemental Analysis
1b
Calcium Carbonate CaCO3
4000.0 3600 3200 2800 2400 2000 1800 1600 1400 1200 1000 800 650.0
55.0
60
65
70
75
80
85
90
95
97.6
cm-1
%T
3298.81
2525.762116.57
1981.061798.12
1645.63
1029.60
874.16
728.39712.65
665.54
1405.89
1082.30
Sample 1B: White layer under blue, Bottom left cloak out side fold.
White pigment on back of all samples
Sample Locations
Sample 1
Sample 3
Sample 1
Location: Bottom left of cloak, outside of fold
Description: Blue
Sample 3Location: Right side, bottom of cloak, inside of foldDescription: Blue
MicroscopicImage
3b
4000.0 3600 3200 2800 2400 2000 1800 1600 1400 1200 1000 800 650.0
83.2
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
98.8
cm-1
%T
3425.77
1647.62
1462.16
1092.011032.30
949.62
874.75
813.92
768.21
740.49
666.95
1137.92
1400.84
1484.26
Sample 3B: Blue Side Down, Right side bottom of cloak, inside fold
Azurite: 2CuCO3 Ca(OH)2
Blue from Cloak
Sample 2
Location: Base, left side toward the back
Description: Green
Sample 4Location: Base, right side toward
the backDescription: Green
MicroscopicImage
2d
Copper Acetate Cu(OH)3 (CH3COO) 5H2O
4000.0 3600 3200 2800 2400 2000 1800 1600 1400 1200 1000 800 650.0
68.4
70
72
74
76
78
80
82
84
86
88
90
92
94
96
97.5
cm-1
%T
3326.07
2923.05
2852.14
1736.301629.80
1554.761451.32
1412.65
1160.041090.25
1038.47
1027.12
871.62
817.77
759.22688.90
Sample 2D: Green base left
Green sample from base
Surprise!!!!
Copper acetoarsenite
Sample 5Location: Flat fold,
left side of cloakDescription: Rust,
metallic, layered, fluorescent under UV light
Pyrite?
MicroscopicImages
We’re no fool!! It is real gold and much more!
Red Ochre: Fe2O3
Red Ochre has been used since prehistoric times. It can be found in volcanic regions or can be produced by heating yellow ochre.
4a
4000.0 3600 3200 2800 2400 2000 1800 1600 1400 1200 1000 800 650.0
73.8
76
78
80
82
84
86
88
90
92
94
96
97.8
cm-1
%T
3290.35
2939.16
1540.26
1449.09
1404.56
1335.35
1236.43
1202.02
1158.25
1080.72
1031.98
1630.89
3068.35
Reference spectrum of hide glue
Glazy part of paint
Sample 6
Location: Book binding
Description: Red, dull
MicroscopicImages
Sample 7Location: Bottom of cloak, left sideDescription: Fiber
7c
4000.0 3600 3200 2800 2400 2000 1800 1600 1400 1200 1000 800 650.0
83.8
85
86
87
88
89
90
91
92
93
94
95
96
97
98
98.5
cm-1
%T
3326.44
2915.79
1637.29
1542.19
1425.311316.01
1203.69
1157.87
1107.50
1052.30
877.04
662.97
1026.68
998.87
981.17
3281.01
Sample 7C: Fiber White end, Bottom of cloak
Blue cloak:AzuriteClayCalcium Carbonate
Green base:Protein/Copper acetoarseniteNot determinedCalcium carbonate
Outer CloakGoldRed Ochre/clay/gypsumCalcium carbonateProtein
Red book binding:Red Ochre/clay/gypsumCalcium carbonateProtein
-Mr. Peter Blume, Director of the Ball State Art Museum
-Bob Galyen, TAWAS
-Ball State Office of the Provost--BSU Teleplex
-Michael Kutis, Geology Technician at Ball State
--Beth Price, Senior Conservation Scientist, Philadelphia Museum of Art
-Dr. Mary Virginia Orna, Scientist-in-Residence, College of New Rochelle
Acknowledgements:
