The Israel Antiquities Authority’s conclusion that the James ossuary inscription is a forgery is based on the results of an oxygen isotope study of a coating covering the inscription area. This inscription coating produced oxygen isotope readings indicating that it was created in modern times, not as the result of a cave environment over thousands of years. The IAA noted that this inscription coating could be the result of a paste made to cover the inscription in order to conceal the forgery or the inscription coating could be a result of cleaning the inscription area.
The IAA never bothered to consider the second possibility—a result of cleaning—that its own report had suggested as an alternative possibility to explain the oxygen isotope reading.
BAR, with its limited resources, has made some attempt to explore this. To understand the issue, some background regarding oxygen isotopes is needed. Oxygen isotope studies express their results as a function of the ratio of two oxygen isotopes—0–16 and 0–18. This ratio is expressed as delta 0–18.