Whenever an exceptional artifact without a provenance appears on the antiquities market, serious questions arise about its authenticity. That is the case with the two ostraca described in the accompanying article.

Obviously the three authors of the scholarly report on the inscriptions are satisfied that the texts are authentic. So are other prominent paleographers who have examined them—including André Lemaire of the Institute of Semitic Studies at the College de France; P. Kyle McCarter, Jr., of Johns Hopkins University; and Frank Moore Cross of Harvard University.

In addition, the ostraca have been subjected to a number of laboratory tests to determine whether they might be fakes.

A Finnish laboratory in Helsinki called Mikrofokus Oy, examined the ostraca with a scanning electron microscope (SEM) fitted with an energy dispersive X-ray microanalyzer (EDS). A SEM-EDS test can determine the elemental composition of the inks, the terra-cotta and any tiny soil fragments or residues on the ostraca’s surfaces.

Previous testing by McCrone Research Institute of Chicago had discovered that the ink on the ostraca is similar in composition to ink from the Dead Sea Scrolls. Mikrofokus Oy confirmed that finding and discovered that the ostraca’s “inscribed surfaces [are] partly covered with a white material” that “seems to cover the terracotta and/or carbon black” (the ink) and “can be scraped off easily.”

The researcher examining the white material reported that the “material is layered … [and] is a mixture of calcite (calcium carbonate) and quartz (most probably grains of quartz from the terracotta).” The summary of the results reads: “The white material … consists of [a lower layer of] small isometric bipyramidal calcite crystals and [an upper layer of] amorphous silica which … forms a thin crust over the crystals.”

In the judgment of the researcher, to produce a two-layered white material of this nature would require “very special conditions and a very long time.” It would also require calcite crystals of a size not commercially available.

The researcher therefore concluded that the white material over the clay and ink was “a natural precipitation product … What is under the white material must then be genuine.”