The patina of the Harpocrate body is not cuprite, and is constituted mainly of chlorides (nantokite, CuCl, and clinoatacamite). The statuette patina also contains chloride (clinoatacamite, Cu 2Cl(OH) 3) and sulphides. The X-ray diffraction done on all objects (except the too small Harpocrate lock of hair background) show that nearly all the patinas are constituted of cuprite, Cu 2O (see the example in Fig. But this cannot be true for the Harpocrate body and the statuette patinas which contain high amounts of chlorine iron in the double aegis patina may also not be a burial residue.

The additional elements Fe, Cl and S might be residues from the burial not eliminated by the restoration. One of the black patinas (the statuette robe) contains neither of these elements, and one contains silver but no gold (the bistoury). Nearly all of them contain gold and from that point of view could be assimilated to ‘black copper’ or ‘black bronze’, but the gold and silver contents are very different, from 0.8 to 16% for gold, from 0 to 9% for silver. A Under 3 MeV protons b Under 6 MeV alpha particlesĮven if one takes into account the fact that the substrate alloys are very different from one object to another, it is clear that the compositions of the patinas are also very diverse.

Patina green copper hair colors