Christian Askeland has posted a very good analysis, Jesus’s Wife Resurrected from Dead, in the blog Evangelical Textual Criticism.
Using two labs, the GJW fragment and a Sahidic John fragment associated with the same papyri lot were carbon dated. The rounded 2-sigma ranges for the manuscripts are as follows:
Only the Harvard report indicates the date of the test (14 March 2014); one might surmise that the second test was ordered after the extremely early date arrived from Arizona. Whatever the case, if one of the two GJW 14C dates were to be accurate, it would probably be the Harvard range (650–870 CE), which is corroborated by the related GJohn manuscript (chart above). Having said this, the result remains somewhat inconclusive. (δ13C levels were also higher than expected, suggesting contamination in all samples.)
So does this confirm the authenticity of the GJW? Such a late dating bulldozes King’s first appraisal of the manuscript as a fourth century witness. The GJW fragment under question is broken on all sides except the top, where apparently the modern forger cut the empty section off of a larger fragment which was in fact ancient. Carbon dating has no value for authenticating such a manuscript, although if the Ptolemaic date (410–200 BCE) offered by the Arizona AMS lab were accurate (of which I am not convinced), fraud would be certain.
If a husband were to genetically test his children to determine whether his wife had been faithful, and the tests returned indicating that that the children could not conclusively be proven to not be his, would this assure him of his wife’s fidelity? Could he then, based upon these tests, be confident that he had indeed fathered the children? Karen King has produced no new evidence to authenticate this fragment. On the contrary, her prior contentions that the GJW fragment was (1) part of a literary codex and (2) was fourth century are now indefensible. Her method of argumentation was not self-critical or objective, but will doubtlessly be sufficient for those who already want to believe.