Collectors Donate Unpapered Antiquities to Museums and Create Problems

The Mexican Museum in San Francisco is moving. It has extensive collections, including archaeological material:

According to the museum’s website, the pre-Hispanic Collection goes back 2,500 years and represents 2,000 pieces encompassing Mesoamerican, Central American and Peruvian cultures. The items include vessels, tools, ceremonial objects and body ornaments from Teotihuacan, Mayan, Zapotec, Nayarit, Colima and Peruvian Incan civilizations. The 83 items that were authenticated include male and female figurines, jars, bowls, vases and necklace ornaments.[...]

In connection with the move, the objects were examined and it was found that there was a problem withmany of the portable antiquities. It was found that almost all of the artefacts described as the oldest in the permanent collection of the Mexican Museum in San Francisco are either forgeries or cannot be authenticated to display in a national museum (Sam Whiting, 'Most of a Mexican Museum collection fails authentication' San Francisco Chronicle  Friday, July 7, 2017).

That’s the finding of a report commissioned by the museum board and submitted in late June by Eduardo Pérez de Heredia Puente, an associate of the National Institute of Anthropology and History in Mexico City. According to the report, only 83 of 2,000 artifacts from the pre-Hispanic, or pre-Columbian, era could be certified as museum-quality by an independent team of museum curators who came from Mexico City to conduct the test. The other 1,917 are considered “decorative,” and will probably be given to schools or smaller museums before the museum moves from its temporary Fort Mason site to a permanent home in a luxury condo tower being constructed near SFMOMA. [...]  The tally of forgeries and decorative pieces will probably grow, because this is just the first of several authentication studies to be done on the museum’s collection of 16,500 items. 

The cause of this problem is that in its early years (the museum was founded in 1975), the museum built its collection on donations from collectors, and basically anything was accepted, without authentication. As we all know, collectors who buy objects from dealers and others without requiring documentation 'grounding' it as an authentic and legal find are very frequently duped by sellers profiting from fraudulent business in forgeries. Accepting unpapered (undocumented) artefact donations from collectors is fraught with risk and reputable public collections avoid them. The Mexican Museum has now museum become more selective about accepting donated artefactsand has turned away pieces which collectors have offered.