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ART authentication Element Analysis

Isabelle van Hoorn PHYS 43, Spring 2014 SRJC + Art Authentication

 Expert Analysis

 Provenance

 Scientific Analysis + Fake or Fortune?

A painting possibly by Claude Monet, owned by David Joel.

• Provenance dating back all the way to the artist himself Traced back through museum records and auction sales

• All international Monet art experts agree on it’s authenticity

• Scientific data of paint analysis shows the pigments used and the painting process are the same as found in other paintings by Monet. + Response from Guy Wildenstein

 “For us this is a matter, not of history of ownership, but of connoisseurship... If David Joel's picture was not included in my father's book, it is because he knew of no paintings in Monet's oeuvre that were executed in the distinctive style of that riverscape... The present members of the Monet Committee came to the same conclusion.” + Scientific Techniques

 Destructive Pigment Analysis

 Microscope

 Infra-red reflectography

 X-ray radiography

Picture from munsell.com + Infrared Reflectography

• Infrared light (300μm>λ> 750 nm) can penetrate deep into the different surface layers of paint. • The IR wavelength is reflected by the white ground and absorbed by darker pigments. • Analyzing the absorption and reflection patterns of the IR radiation can tell us a lot about what elements were used by the artist. • Often artists use charcoal or carbon black for their underdrawing, making this now visible to the infrared camera, sometimes revealing different images all together.

+ The Old Guitarist Picasso

+ X-ray

 Wilhelm Conrad Röntgen

 First Nobel Prize in Physics 1901

"in recognition of the extraordinary services he has rendered by the discovery of the remarkable rays subsequently named after him".

Picture of hand of his wife in 1896 Wilhelm Rontgen, picture from nobelprize.org Picture taken from worldfamousphotos.com +

 Soon after the discovery of X-rays Charles Glover Barkla discovered that each element has its own characteristic x- ray spectrum. (Nobel Prize Physics 1917)

 Sir William Henry Bragg and his son, Sir William Lawrence Bragg, were then able to experimentally prove that the discrete electron energy levels of an atom existed. (an idea proposed by Niels Bohr)

 Henry Moseley showed that each element’s characteristic x-ray energy spectrum followed the predictions of the Bohr atomic model.

 He organized his data in a diagram, now known as the Moseley diagram. It displays a linear relationship between an atom’s atomic number and the square root of the frequency of its atomic x-ray. This diagram was the first way that scientists were able to definitively establish the atomic numbers of the elements.

Moseley Diagram Picture taken from ie.lbl.gov + X-Ray Fluorescence Characteristic X-ray Analysis

 X-rays with greater energy than the binding energy of the inner electrons can eject the electrons out of the atom.

 The vacant spot gets replaced by electrons from the outer shells, which in turn radiate their energy out as they fall into a lower

energy state. Picture taken from projects.exeter.ac.uk

 The emitted x-ray photons have a characteristic energy E=hf

 Every element has its own characteristic x- ray spectrum and by measuring the energy or wavelength of the radiated x-ray, you can determine the element of the sample.

Picture taken from olympus-ims.com + Process

Picture taken from webexhibits.org + Pigments Through The Ages

John Constable (1776-1837) 1.Chrome Yellow 2.Prussian Blue 3.Verdigris Green 4. Emerald Green

Pictures taken from webexhibits.org + St. Peter – Fake or Fortune?

 Appears to be from Renaissance and Baroque Period (1400-1600)

 We want to find pigments such as: vermillion red, azurite blue, and lead white.

 We want to find pigments such as: cobalt blue, cadmium yellow, or zinc white. Since these pigments were not used yet until after 1800.

 We do want to find an underdrawing as most artist first sketched their work with carbon black during this time period.

+ Work Cited  http://munsell.com/color-blog/chemistry-fireworks-colors/

 http://www.worldsfamousphotos.com/2007/03/28/first-x-ray-1896/

 http://www.nobelprize.org/nobel_prizes/physics/laureates/1901/

 http://projects.exeter.ac.uk/geomincentre/estuary/Main/fluorescence.htm

 http://www.olympus-ims.com/en/applications/portable-xrf-technology-archaeometry-authentication- conservation-art-objects/

 http://www.webexhibits.org/pigments/intro/history.html

 http://www.petroz.com/manet/gem.htm