e-conservation the online Magazine 16, oct 2010.pdf

REVIEWS
The afternoon session focused on four different
themes: smalt pigment quantitative EDX analysis;
medieval window flashed glass composition, structure
and manufacturing processes; organic remains
preserved by metal corrosion products;
and a multi-analytical study of the pigments in
17 th century Portuguese tiles (“azulejos”). The
first presentation, by Marika Spring, introduced
several examples of SEM-EDX analysis on smalt
samples from a number of paintings in the National
Gallery ranging in date and geographical
origin. The variations in arsenic content as well
as possible effects of arsenic on the properties
of the glass were discussed. The effect of various
factors such as pressure, beam gas and working
distance on the degree of beam skirting and on
quantitative analysis were also focused.
The poster session continued during the tea break.
In the last session of the day the speakers brought
into discussion very distinct topics, such as the
investigation of medieval opaque glasses and
enamels, analyses of chrome-yellow and chromeorange
dyestuffs used for domestic and imported
cotton fabrics “Touzan” (a vertically stripped Japanese
fabric) in the 19 th century, and the study
of inscriptions, filing and polishing marks on the
bronze weapons from the Qin Terracotta Army in
China.
The first day ended with a reception at the Addis
Gallery, in the British Museum.
The second day started with a presentation by
Shirley Northover, focused on the application of
electron backscattered diffraction (EBSD) in archaeology.
EBSD patterns are characteristic of the structure
and local crystallography orientation of the
material under the beam. By systematically collecting
and analysing these patterns, maps can
be built up revealing the distribution of present
phases, showing grain sizes and shapes, and giving
“Quantitative EDX analysis of smalt pigment in the variable
pressure SEM”, by Marika Spring.
information on the deformation levels of the surface.
Hector Lozano spoke on the re-discovery of
Mexican feathered textile, a very peculiar technique,
of which only six known textiles still exist,
all of them from the 17 th and 18 th centuries. In
this case SEM was used to identify the materials
present in the feathered yarns particularly the
identification of the birds from which the feathers
were obtained. The next communication was
on the study of raw materials used in the production
of Chinese porcelain and stoneware bodies,
and the last one of the session was on the role of
SEM-based charcoal identification on reconstructing
vegetation changes in the last 40,000 years in
Western Cape (South Africa). The afternoon presentations
were followed by the second poster session.
The sixth session began with a presentation from
Diane Johnson on the subsurface analysis by application
of a focused ion beam scanning electron
microscope (FIBSEM) to samples of geological
(fossils and meteorites) and historical importance.
Next, Alicia Perea talked on gold usage and
the analysis of wear marks and/or deterioration in
site condition of gold artefacts and how difficult
it could be to differentiate one from the other.
Carol Pottasch presented a study on a rediscovered
Dutch painter, Adriaen Coorte (works dating from
10 e-conservation