Which stone does the Hebrew leshem, rendered ligure in the King James Version, actually name?

No securely dated ancient Hebrew source uses leshem outside the Exodus breastplate list in a context that fixes what stone it names, so every proposed identification, jacinth, amber, tourmaline or opal, rests on inference rather than direct attestation. The Septuagint, the Vulgate and the later translation tradition do not agree on a referent for this ninth breastplate stone either, which is the visible symptom of the unsettled identification.