According to the paper by Joseph Kohlbeck and Eugenia Nitowski published in Biblical Archaeology Review in 1986, “further analysis was conducted by Dr. Riccardo Levi-Setti of the Enrico Fermi Institute of the University of Chicago who put both shroud and Jerusalem samples through his high-resolution scanning ion microprobe and produced graphs; these graphs revealed that the samples were an unusually close match, except for the minute pieces of flax that could not be separated from the shroud’s calcium and caused a slight organic variation.” As there is no mention of any control investigation, it is not obvious from this statement how Kohlbeck and Nitowski could know that the match was “unusually close.”
The article is accompanied by the diagram below, and the caption beneath::
“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 fibres and in Jerusalem first-century tombs. The peaks on each graph indicate the ions from a particular chemical compound. The graphs of positive and negative ions reveal strikingly similar patterns for the limestone from the Jerusalem tomb and limestone adhering to the shroud fibres. This similarity, though not proof, suggests the possibility of a Jerusalem provenance for the shroud limestone.”
Certainly we can see gross similarities. All four graphs show four main clumps of peaks, which more or less correspond, particularly as regards the positive secondary ions in the lower pair. However, the count numbers are very different, a factor obscured by the logarithmic X-axis, which makes, for example, a ten-times difference between two ion counts appears as if the larger is only twice, or less, as big as the smaller. The graphs most certainly do not “reveal strikingly similar patterns for the limestone from the Jerusalem tomb and limestone adhering to the shroud.” Quite the reverse.
Fortunately, Eugenia Nitowski, now also called Sister Damian of the Cross, included larger and clearer versions of these graphs in an unpublished paper called “The Field and Laboratory Report of the Environmental Study of the Shroud in Jerusalem.” Below, the positive ion count graphs have been superimposed on a grid and the value of each peak estimated (blue dots).
As some peaks were combinations of different ions, they have not been considered further here.
To establish whether these readings are at all meaningful, I compared the ratio of the isotopes of magnesium, silicon, calcium and gallium to their global proportions.
Allowing for the imprecision of the readings from the original graphs, and for local variations in isotopic ratios, these figures suggest that the heights of the peaks of the elements on Levi-Setti’s original graphs are truly representative of their quantities. The overall proportions of each element in each sample can then be calculated.
This is surely diagnostic, and clearly shows that the two samples are different. The proportion of silicon to calcium/magnesium, for example, reflects the proportion of quartz to carbonate in the rock. The Jerusalem sample is overwhelmingly carbonate (about 0.3% silicon); the Shroud sample is 7% silicon.
The proportion of magnesium to calcium may reflect the proportion of dolomite (calcium magnesium carbonate) to calcium carbonate, or simply the replacement of calcium atoms by magnesium. The Jerusalem sample has 2% magnesium to 98% calcium; the Shroud sample has 15% magnesium to 85% calcium.
On the face of it, this is fairly conclusive evidence that the limestone found on the Shroud is not from Jerusalem.
In 1986, Lore Holmes and colleagues investigated the trace elements in medieval sculptures and in medieval quarries in France, with the aim of being able to match each sculpture to its quarry. (Lore L. Holmes, Charles T. Little & Edward V. Sayre, ‘Elemental Characterization of Medieval Limestone Sculpture from Parisian and Burgundian Sources,’ Journal of Field Archaeology, Vol. 13, No. 4). Rock from two quarries in the middle of Paris was analysed, one of which was found to be “relatively pure calcium carbonate” (Port Mahon), while another, about a mile away, was “essentially pure calcite in which about 13% of the calcium ions have been replaced by magnesium ions” (Val-de-Grâce). This 87/13 Ca/Mg ratio looks very similar to the 85/15 ratio found on the Shroud.
That is not to say, of course, that the limestone found on the Shroud must have come from Paris. No doubt there are limestones all over the world with varying proportions of calcium to magnesium atoms, and varying proportions of quartz to carbonates. However, it reinforces the conclusion that the limestone samples analysed on the Shroud and from the Damascus Gate are not from the same source.
In 2012, Gérard Lucotte published an analysis of the mineral particles he found on a sticky tape sample taken from the epsilon blood-stain by Giovanni Riggi di Numana (‘Optical and Chemical Characteristics of the Mineral Particles Found on the Face of the Turin Shroud,’ Scientific Research and Essays Vol. 7). Of the first 500 particles he examined, 82% were mineral (the others being organic: 14%, and metal: 2%), but he does not clearly enumerate further findings. About half the mineral particles were “clays.” There were, however, significant quantities of carbonates, and significant quantities of the carbonates (50 particles) were dolomitic – containing roughly equal amounts of both calcium and magnesium. This implies an approximate 10-20% proportion of magnesium in the limestone, supporting Levi-Setti’s analysis of the Shroud’s limestone, and confirming that it does not resemble the Jerusalem sample analysed.
As a side note, Riccardo Levi-Setti was a true giant in the field of ion microscopy, and the inventor of the scanning ion microprobe used here. He was also an expert on trilobites, and the analysis of their carboniferous carapaces. It is inconceivable that he was not well aware of the difference between the two samples he was given to study. Any subsequent misunderstanding must have been due to Kohlbeck and Nitowski.