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PRESERVATION: THE SCIENCES IN ART AND ART HISTORY
by Steve Rees, News Editor
The Point News
http://thepointnews.com/2011/03/preservation-the-sciences-in-art-and-art-history
March 1 2011
On Feb. 23, United States Library of Congress preservation research
scientist Lynn Brostoff presented her studies of ancient artifacts and
works of art using scientific methods in her lecture "Using Science
to Unlock the Secrets of Art and Historic Artifacts" as part of the
Natural Science and Mathematics Colloquium series.
Given in the Schaefer Hall lecture room, Brostoff's lecture focused
on her role in the field of cultural heritage science, which includes
elements of biology, chemistry, physics, forensics, and materials
science (the analysis of how an object's properties are linked to
its atomic and molecular structure).
"We're doing a lot of material science," said Brostoff, "and what
the materials present say about the condition of the object."
Brostoff discussed how the analytical study of museum and library
collections is based on technical studies, model studies of degradation
mechanisms, and conservation methods development.
Technical studies refers to the study of a material's identity,
methods of manufacture, the history of the manufacturer, innovations
of certain components of the object, and the context of the object
in relation to its found location.
"A lot of people develop analytical tools specifically for the
applications we have," she said. "The first thing we want to do is
look at things non-invasively."
Electromagnetic (EM) radiation is the primary method that scientists
like Brostoff use to analyze artifacts non-invasively.
The EM waves are scattered, reflected, transmitted, and absorbed by
different objects, the results of which are detected and analyzed to
understand more about the artifacts in question.
Microscopy, spectral imaging, and Raman spectroscopy are other methods
of analyzing these materials.
When more analytical techniques are needed, the next stage of object
investigation is the use of minimally invasive techniques, which
includes calorimetry and even fold endurance testing on micro-samples
of the object.
Brostoff discussed examples of several artifacts analyzed by the
preservation staff of the Library of Congress, including a fifteenth
century version of the Armenian Gospel from Verin Noravank Monastery
in Siwnik (Syunik Province), Armenia.
The book itself was acquired by the Library of Congress in 2008,
and has since been under intensive technical study.
The objective of working with the book is to preserve the colors and
text of the Gospel of St. Mark, which is inside the book.
Beginning with X-ray fluorescence, or the use of X-rays to excite
electrons of atoms on the surface enough to cause a detectable energy
release, Brostoff explained how the artifact was analyzed in terms
of the colors used on one of the pages.
The X-ray fluorescence, or XRF, detected tin oxide in the work, a rare
white pigment that was used to make the white color used on the pages.
XRF also detected smalt (a cobalt glass material from arsenic ore)
used for the blue in the book's pages. This finding was especially
surprising, as it was thought that smalt was not used until Venetian
paintings over a century later.
Further analysis of the blue pigments on the page with Fourier transfer
infrared spectroscopy (FTIR) indicated the presence of ultramarine,
a silicon oxide compound also known as lapis lazuli, found almost
exclusively in what is now Afghanistan.
Further cobalt traces indicating smalt presence were verified with
elemental analysis. Doing all of these tests aided in accurate
identification of the pigment compounds.
"We could have missed the pigment elements by doing only one analytical
technique," said Brostoff.
The red pigment of the page was analyzed and found to contain mercury
and lead, common sources of red in other works at the time.
Further analysis with micro-XRD indicated lead tetroxide for the lead
source, and mercury sulfide for the mercury source.
The fact that all of these different compounds could be used for the
painting makes more sense given the proximity of Syunik to the Silk
Road, the main trade route of the time.
The Persian influence can even be seen in the pages' artwork.
"There is little known about Armenian painting," said Brostoff,
"so this told us a lot."
Another method of analysis used by the lab is laser ablation
inductively-coupled mass spectrometry (LA-ICP-MS), which was used to
analyze trace elements of Ancient Chinese gold.
XRF was also used to analyze the moon dust left on the space suits
of astronauts from the Apollo 17 mission.
"You can never see with the naked eye where we've been," said
Brostoff. "And digitizing does not replace study and analysis."
"I thought the lecture was interesting," said Kevin Tennyson, a
first-year Physics student who attended the talk.
"I have an appreciation for the physics of it, and the materials
science that I personally would not have thought of."
From: A. Papazian
by Steve Rees, News Editor
The Point News
http://thepointnews.com/2011/03/preservation-the-sciences-in-art-and-art-history
March 1 2011
On Feb. 23, United States Library of Congress preservation research
scientist Lynn Brostoff presented her studies of ancient artifacts and
works of art using scientific methods in her lecture "Using Science
to Unlock the Secrets of Art and Historic Artifacts" as part of the
Natural Science and Mathematics Colloquium series.
Given in the Schaefer Hall lecture room, Brostoff's lecture focused
on her role in the field of cultural heritage science, which includes
elements of biology, chemistry, physics, forensics, and materials
science (the analysis of how an object's properties are linked to
its atomic and molecular structure).
"We're doing a lot of material science," said Brostoff, "and what
the materials present say about the condition of the object."
Brostoff discussed how the analytical study of museum and library
collections is based on technical studies, model studies of degradation
mechanisms, and conservation methods development.
Technical studies refers to the study of a material's identity,
methods of manufacture, the history of the manufacturer, innovations
of certain components of the object, and the context of the object
in relation to its found location.
"A lot of people develop analytical tools specifically for the
applications we have," she said. "The first thing we want to do is
look at things non-invasively."
Electromagnetic (EM) radiation is the primary method that scientists
like Brostoff use to analyze artifacts non-invasively.
The EM waves are scattered, reflected, transmitted, and absorbed by
different objects, the results of which are detected and analyzed to
understand more about the artifacts in question.
Microscopy, spectral imaging, and Raman spectroscopy are other methods
of analyzing these materials.
When more analytical techniques are needed, the next stage of object
investigation is the use of minimally invasive techniques, which
includes calorimetry and even fold endurance testing on micro-samples
of the object.
Brostoff discussed examples of several artifacts analyzed by the
preservation staff of the Library of Congress, including a fifteenth
century version of the Armenian Gospel from Verin Noravank Monastery
in Siwnik (Syunik Province), Armenia.
The book itself was acquired by the Library of Congress in 2008,
and has since been under intensive technical study.
The objective of working with the book is to preserve the colors and
text of the Gospel of St. Mark, which is inside the book.
Beginning with X-ray fluorescence, or the use of X-rays to excite
electrons of atoms on the surface enough to cause a detectable energy
release, Brostoff explained how the artifact was analyzed in terms
of the colors used on one of the pages.
The X-ray fluorescence, or XRF, detected tin oxide in the work, a rare
white pigment that was used to make the white color used on the pages.
XRF also detected smalt (a cobalt glass material from arsenic ore)
used for the blue in the book's pages. This finding was especially
surprising, as it was thought that smalt was not used until Venetian
paintings over a century later.
Further analysis of the blue pigments on the page with Fourier transfer
infrared spectroscopy (FTIR) indicated the presence of ultramarine,
a silicon oxide compound also known as lapis lazuli, found almost
exclusively in what is now Afghanistan.
Further cobalt traces indicating smalt presence were verified with
elemental analysis. Doing all of these tests aided in accurate
identification of the pigment compounds.
"We could have missed the pigment elements by doing only one analytical
technique," said Brostoff.
The red pigment of the page was analyzed and found to contain mercury
and lead, common sources of red in other works at the time.
Further analysis with micro-XRD indicated lead tetroxide for the lead
source, and mercury sulfide for the mercury source.
The fact that all of these different compounds could be used for the
painting makes more sense given the proximity of Syunik to the Silk
Road, the main trade route of the time.
The Persian influence can even be seen in the pages' artwork.
"There is little known about Armenian painting," said Brostoff,
"so this told us a lot."
Another method of analysis used by the lab is laser ablation
inductively-coupled mass spectrometry (LA-ICP-MS), which was used to
analyze trace elements of Ancient Chinese gold.
XRF was also used to analyze the moon dust left on the space suits
of astronauts from the Apollo 17 mission.
"You can never see with the naked eye where we've been," said
Brostoff. "And digitizing does not replace study and analysis."
"I thought the lecture was interesting," said Kevin Tennyson, a
first-year Physics student who attended the talk.
"I have an appreciation for the physics of it, and the materials
science that I personally would not have thought of."
From: A. Papazian