Being a professional conservator of many years I thought that I would clarify our role in this topic.

Conservators don't "authenticate" art or objects. As a matter of fact that is expressly stated in our professional code of ethics. What a knowledgable conservator can do is to examine the materials that compose an object, perhaps take small samples if required, and characterize those materials. What we can do is to rule certain things out - if a supposed rennaisance painting contains titanium white pigment, for example, then there has to be an explantion why a much later pigment is there (perhaps a later overpaint? perhaps a fake?).

In one instance, some years ago, I was asked to examine a supposed 16th century cast iron mortar that was a "found" artifact from a site (not excavated by a professional archaeologist). This thing was being considered for acccession by the musuem I worked for at the time. I took a tiny sample of the metal and corrosion and examined it metallographically. It turned out to be completely pure iron - large ferrite grains with absolutley no carbon and extremely small and well distributed slag inclusions. I did a little historical research and such a pure iron did not exit, nor could be cast, until the 1880's. I stated that fact in my report. The curator invovled scoffed at first, but I said that the attributed age was unlikely unless someone had made a significant metallurigcal discovery well in advance of the date established by historians. A month later the curator excitedly pulled me over and showed me the very same cast iron mortar, used for fireworks, from a 1940's Sears and Roebuck catalog.

The very best approach to authentication is one that involves several disciplines - curators, conservators, historians, scientists, and others have their own perspectives that usually can shine light on whether something is as represented when being considered or reconsidered by a musuem.

Cheers!
Dave

David Harvey
Conservator
Los Angeles, California  USA