Silver and Gold on the Hairs of Holy Maria-Magdalena, Studied by Scanning Electron Microscopy and Elemental Analysis

We have studied by optical microscopy and by SEM-EDX some metallic particles of silver and gold adhering to the Maria-Magdalena hairs. The presence of silver particles is explained by the contact between hairs and the inner side made of silver of the initial reliquary where Maria-Magdalena remains were kept. Presence of gold particles is also explained by the contact between hairs and the gold of the bust-reliquary where hairs of Maria-Magdalena hairs were kept between 1283 and 1793. Silver and Gold on the Hairs of Holy Ma-ria-Magdalena, Studied by Scanning Electron

DOI: 10.4236/ad.2019.74012 258 Archaeological Discovery chemical analyses). We have published these last years the mitochondrial DNA haplogroup found by extracting genomic DNA from the bulb of hair number 10 (Lucotte, 2016), the explanation of the brown-red observed colour of the hairs by scanning electron microscopic characterisation of its melanosomes (Lucotte & Thomasset, 2017a), the description of some fennel rests on or at the vicinity of some of these hairs (Lucotte et al., 2018) and marine micro-remains loaded on the hairs (Lucotte et al., 2019).
In the present study, we describe and analyse silver and gold metallic deposits on some of these hairs, by SEM (Scanning Electron Microscopy) and EDX (Energy Dispersive X-ray spectroscopy) analysis.

Material and Methods
The material is ten of the lock of Maria-Magdalena's hairs that were kept in the dedicated reliquary located in the Saint-Maximin basilica. These hairs, numbered 1 to 10, were loaded on a sterile sticky paper for optical microscopy, SEM and EDX analysis.
All the hairs were examined in confocal stereoscopic micrography. The SEM apparatus used for metallic deposits observations is the FEI model Quanta FEG (an environmental electron microscope apparatus). Elemental analysis of deposits was achieved by using EDX, this SEM microscope being equipped with the probe model X-flash 6/30. Both LFD (Large Field Detector) and CBS (Circular Back Scattering) were used, the last one to better detect heavy elements. Each elemental analysis is given in the form of a spectrum, with kiloelectrons/Volts (ke/V) on the abscissa and elemental peaks heights (cps/eV) in ordinates.

Results and Discussion
There are numerous particles of silver and of gold on the surface of hair numbers 1, 2, 3, 4 and 9. As an example Figure 1 shows an optical view of some portion of hair number 2 where silver is present under the form of a longitudinal line running along all the hair border, and gold under the form of three local deposits. Figure 2 shows a MEB photograph of some part of the longitudinal line; EDX analysis establishes that it is mainly compounded of silver (of the chloride form, which is the most stable). Two other parts of the line are shown on Figure 3, which are of the same elemental composition. In a fourth part of the line ( Figure   4), the height of the chlorine peak is as elevated as that of the silver main peak.

Silver
Figure 5 shows a granulous particle (of about 3 µm of length), located on hair number 1. Elemental analysis of this particle establishes that it is compounded of a mixture of silver chloride and sulphide. Figure 6 shows another particle, also located on hair number 1 that is of silver sulphide with gold. Figure 7 shows another particle located on hair number 2 that is a plaque (of more than 5 µm of        Figure 9 is a SEM photograph of one of the three particles of gold, depicted on Figure 1, located on hair number 2; it is a multi-lobed particle of about 1.5 µm of maximal length. Its elemental analysis establishes that it is mainly compounded of gold (in fact an alloy, with 8.5% of silver and 2.2% of copper). The sulphur content in the sample is, as for all of the gold particles studied here, more elevated than that found in ancient hairs (Lucotte & Thomasset, 2017b); it is deduced that this elemental level in sulphur is mainly due to pollution. The composition of the particle located on hair number 3 ( Figure 10) is also that of an alloy of gold, silver and copper. But in the plaque, also located on hair number 3 (Figure 11), the alloy is mainly of gold with traces of copper; it is also the case for a second smaller plaque (Figure 12), located on hair number 1, and for a third plaque ( Figure 13), but with silver, located on hair number 1. Figure 14 shows an example of grains of gold dust, located on hair number 9. Figure 15 shows examples of two little particles of gold (of a gold powder), located on hair number 3. Figure 16 shows an example of a scale of pure gold, of a relatively great size (of more than 2 µm of maximal length), which is located on hair number 9.

Copper
There is only one piece of pure copper (Supplementary Figure 1). It is a little plaque of this metal, located on the surface of hair number 3. Most of the copper-compounded pieces found are particle of brass: Supplementary Figure 2 shows one of them, also located on hair number 3; there are other plaques of brass, located near hair number 6 and between hairs 9 and 10. Probably they are fragments pulled up to the metal of the reliquary. Supplementary Figure 3 shows a group of little copper-made particles (calibrated at about 5 µm of length, and of a manufactured form), located on some part of hair number 6. Elemental analyses establish that they are particles of copper sulphate; they are powder members of a classical phytosanitary product. Such groups of copper sulphate particles occur also on two other parts of hair number 6, and on hair number 10.

Lead
There is only one piece compounded of lead (Supplementary Figure 4), that is located on hair number 9. It is a round (less than 5 µm) particle of composite appearance; elemental analysis establishes that it corresponds to lead phosphate, another phytosanitary product used in the past.

Iron
Supplementary Figure 5 shows a little white-to-electrons particle, located on the hair number 3 border. Elemental analysis establishes that it is a particle of iron oxide, a metallic industrial pollutant commonly found in all samples stu-     particles are present in number on hairs numbers 1, 2 and 6. Supplementary Figure 6 shows a white-to-electrons particle, located on the hair number 6 border near a transversal alteration of that hair. It is complex in form, compounded of little spherical (showing that it corresponds to some material in fusion) sub-particles. Elemental analysis establishes that it is mainly of pure iron. Such spherical sub-particles, isolated or lumped together, were found on the surfaces of hairs numbers 1, 2 and 3. There are also numerous little particles (of pure or of oxided iron), of various forms, on all hair surfaces; they correspond to common industrial modern pollutants. Supplementary Figure 7 shows a very little (of about 1 µm) particle, located on hair number 1. It is compounded of iron sulphate, a third common phytosanitary product. Such particles, in isolated form or in groups, are found on hair number 2, 3, 5, 9 and 10.

Titanium
Supplementary Figure 8 shows a rod of titanium, located on some part of hair number 3. It is compounded of titanium dioxide (TiO 2 ), the most common metallic pollutant after iron. Two other samples of such a rod are found on other parts of hair number 3. Supplementary Figure 9 shows a micro-ball of titanium, located on hair number 10 (elemental analysis establishes that titanium is the metallic component of this micro-ball). This unique observation corresponds probably to a droplet of modern white colorant (of titanium), loaded on a bed of calcium carbonate.

Aluminium
Supplementary Figure

Mercury
Supplementary Figure 11 and Supplementary Figure 12 show two micro-drops of mercury, located on hair number 1. Elemental analysis of these micro-drops shows that they are compounded of cinnabar (HgS), a red colorant used since the Middle Age to imitate blood spots . A third micro-drop of cinnabar, located on hair number 3, is shown on Supplementary  Figure 13.

Calcium Phosphate Particles
All of the ten hairs studied have deposits of calcium phosphate on their surfaces. That is important to consider, because hydroxyapatite remains the mineral component found in ancient bones (Lucotte & Thomasset, 2017c). In some cases the calcium phosphate deposit is very thin ( Figure 17); but often this thin deposit is arranged in longitudinal line running along the hair surface ( Figure 18). Locally the calcium phosphate deposit can also be thick (with more mineral matter contained in its), constituting a bone scale with acute borders ( Figure 19).  In summary, I found on the hairs numerous particles of silver and gold, but also some metallic particles of copper, lead, iron, titanium, aluminium and mercury. All the hairs have deposits of calcium phosphate on their surfaces.       a thin bone scale  a thick bone scale Figure 20 7  three thick deposits arranged longitudinally 9  two thin deposits  a thick plaque Figure 21 Table 2 summarizes all the observations of gold particles on hairs. Probably most of them (particularly those that are of pure gold) are due to close contact between hairs and the gold of the bust-reliquary and that of the crown.
Silver particles (   a plaque of gold alloy (Au/Ag)  Four little particles of a gold powder  two little particles of a gold powder  two little particles of a gold alloy (Au/Ag/Cu) powder  a second plaque of gold alloy (Au/Ag/Cu) Figure 12 Figure 13 2  three little particles of a gold alloy (Au/Ag/Cu) powder  a little poly-lobed particle of a gold alloy (Au/Ag/Cu)  six little particles of a gold powder Figure 9 3  a particle of gold alloy (Au/Ag/Cu)  a plaque of gold alloy (Au/Cu)  two particles of gold alloy (Au/Ag/Cu)  three particles of a gold alloy (Au/Ag/Cu) of a powder   Table 3. Silver deposits found on hairs.
Hair number Different sorts Corresponding figures 1  a particle that is a mixture of silver sulphide and chloride  a particle of silver sulphide and gold  a plaque of silver with copper  a granulous particle of silver sulphide  a little particle of silver sulphide  3  a little plaque of silver sulphide  a particle of silver sulphide/chloride  many little plaques of silver sulphide (with copper traces), arranged longitudinally  two little plaques of silver sulphide  eight little plaques of silver sulphide arranged longitudinally  a turmoiled little particle of silver sulphide 4  a large plaque of pure silver Figure 8 9  two little plaques of silver sulphide  one little pile of particles of silver sulphide, with copper silver reliquary; possibly some of the silver particles observed on hairs were due to initial contact with the inner side of the reliquary.

Conclusion
We observed on all hairs studied many deposits of calcium phosphate. Such observations indicate a previous close contact between hairs and some bone. We know that hairs covered cranium in the historical (between 1283 and 1793) bust-reliquary (see Figure 22) where Maria-Magdalena remains were kept. It is during this long time period that the hydroxyapatite of the cranium loaded on hairs.
Because the bust-reliquary was of gold (and also the crown that covered hairs), some of the gold plaques observed on some hairs (particularly those that are of pure gold, like that of Figure 16) can be detached among time from the gold of the bust-reliquary to the hair surface. Generally, gold particles deposited on hairs are made of an alloy of gold with little amounts of silver and copper.
The numerous plaques or silver sulphide (or/and chloride) observed at the surface of some hairs are more difficult to explain; often these plaques are also orientated in longitudinal lines along the hair surface. Because we know that the initial (since 1281) reliquary where the Maria-Magdalena remains were kept was of silver, we suppose that some of the silver plaques observed (particularly those that are of pure silver, like that of Figure 8) were also detached among time from the silver of the inner side of this reliquary.
Other metallic particles observed at the hair surfaces are in fact explained as residues of deposits from the current reliquary, or as traces of phytosanitary products or colorants, or as modern industrial metallic pollutants.   Above: SEM photograph (in CBS, 5000×) of the particles (4: particle of iron sulphate; 3: particle of copper sulphate; 5: two particles of calcite). Upper spectrum (that of particle 4). C: carbon; O: oxygen; Fe (three peaks): iron; Na: sodium; Mg: magnesium; Al: aluminium; Si: silicium; S (two peaks): sulphur; K: potassium; Ca (two peaks): calcium. Lower spectrum (that of particle 3).C: carbon; O: oxygen; Cu (three peaks): copper; Na: sodium; Mg: magnesium; Al: aluminium; S (two peaks): sulphur; K: potassium; Ca (two peaks): calcium; that spectrum corresponds to a particle of copper sulphate.