This investigation set out to identify the ninth breastplate stone and stopped without a conclusion, because every avenue it examined turned out to be inferential. The ancient versions disagree and none of them is independent of the others; comparison with neighbouring stone lists establishes what was available rather than what was meant; and etymology alone has not narrowed the four candidates. Nobody holds a defended position that a specialist could go and read against a rival one, so this is a gap rather than a disagreement.
What would resolve this A securely dated use of leshem outside the two Exodus lists, in a Hebrew or closely related Northwest Semitic text, in a context that identifies a physical object. Failing that, a labelled or securely provenanced stone from a Second Temple period priestly context, or a decisive argument from Semitic cognates. Absent one of those, the honest answer is that the question may not be decidable on present evidence, and establishing that would itself be a result.
OpenNorthwest Semitic philology, biblical archaeology and historical gemologyMircea Eliade (ed.); Lindsay Jones (ed., 2nd ed.), Encyclopedia of Religion