Why And When To Perform A Metallographic Examination
A metallographic examination can provide extremely strong scientific evidence of age, or the lack thereof, as well as revealing the method of manufacture, and the presence of natural or artificially induced corrosion. It should be considered essential in the authentication of certain types of artifacts.
Once an object has been examined to identify areas of likely restoration or tampering, samples can be removed or, if possible, an in situ examination can be performed. If there is any question of potential tampering, a radiograph is generally recommended.
It may be desirable to sample some restoration material, to determine if the work was performed in antiquity, or in more modern times.
A metallographic examination can find evidence of age, structural stress and even the methods used to manufacture a metal object. It is often a conclusive tool in identifying metal forgeries, though the information is often combined with a metallurgical analysis.
A minimally invasive type of examination can be performed in situ on a polished site on some objects.
When removal of a metal sample is required, it can often be quite small, and taken from an area where it is not readily noticeable.
It can provide extremely strong evidence of advanced age, or the lack thereof, and may even be the only test necessary to identify some forgeries.
The cost of the equipment and the subsequent test used can be reasonable, and well within the means of many dealers and collectors.
There is a large database for comparison.
The samples are not destroyed in testing, and the same sample can be used for certain other types of metallurgical analysis.
It is a destructive test, generally requiring the removal of a sample. To date, no completely non-invasive comparable procedure exists.
It requires significant training to correctly interpret some samples, particularly high-quality forgeries.
The cost of the test can be moderately expensive, when contracting examination services with some agencies.
Preparation of some samples may require toxic or dangerous chemicals.