Comparison of limestone samples from a Jerusalem tomb with limestone from the linen fibers of the Shroud of Turin. These two graphs plot the relative amounts of the chemical compounds found in thin sections of aragonite, the particular crystalline form of calcium carbonate present both on the shroud fibers and in Jerusalem first century tombs. The peaks on each graph indicate the ions from a particular chemical compound. This graphs of negative secondary ions reveals strikingly similar patterns for the limestone from the Jerusalem tomb and the limestone adhering to the shroud fibers. This similarity, though not proof, suggests the possibility of a Jerusalem provenance for the shroud limestone.