Slowly, and sometimes begrudgingly, the trained eye of the expert is giving way to scientific techniques in the detection of art forgery. It is unlikely that the technician will ever replace the connoisseur, but the laboratory is playing an ever more important role in the examination of artwork, especially when the values reach into the millions of dollars.
Nowhere is that advance more evident than at the J. Paul Getty Museum, which has become a pioneer in the use of scientific analysis. The most dramatic application came in 1983, when the authenticity of its sculpture of a Greek youth, known as a kouros, came under challenge by some scholars.
The kouros, a marble figure that dates to 500 BC, is one of the Getty's most prized acquisitions. Only 13 intact kuroi are known to exist; one person with close ties to the Getty says the museum paid more than $6 million for the figure.
Marble statuary is one of the most difficult art forms to analyze scientifically, largely because marble resists the kind of decay that occurs in most other media. It is the decay that science is usually able to measure. Nonetheless, the Getty asked Stanley Margolis, a geology professor at the University of California, Davis, to investigate.
He spent more than a year on the project and eventually applied techniques that had not previously been used in the art world, including the use of X-ray diffraction to determine mineral composition and analysis of core samples taken from breaks in the statue's legs.
Margolis, joined by scientists at other universities and at the Getty, eventually was able to determine roughly where the kouros marble was quarried and whether a very thin crust on the statue was the product of natural or artificial aging. Margolis concluded--at least to his satisfaction and that of the Getty--that the aging was natural. Shortly afterward the museum published an article in a scholarly journal expressing its confidence in the authenticity of the piece.
A similar dilemma faces the Getty with challenges to two other pieces, the Head of Achilles and an archaic grave relief. Both are million-dollar works, according to sources close to the museum, and the museum may repeat the experiments it used with the kouros.
The results may be more difficult to achieve this time, however. According to Margolis, the kouros was carved from dolomite marble and had acquired an unusual crust in the 2,500 years since it was made. The crust was the principle feature used in the analysis.
The Achilles head and the grave relief are made from calcite marble, a form that does not produce the same type of crust. To augment his work on the two pieces, Margolis has proposed what he admits is a radical procedure: the drilling of tiny core samples from the worked surface of both pieces. This is roughly equivalent to suggesting that small amounts of paint be scraped from the surface of the Mona Lisa and has caused some debate among officials at the Getty. A decision on the project is expected this summer.