Why Blood Stains on the Turin Shroud are of Red Colours? Optical Microscopy Studies and SEM-EDX Analyses

We review here previous and actual results concerning sixty-nine particles and sub-particles located at the surface of a sample of the Turin Shroud taken in a blood stain of the Face. These artificial products (nine hematites, nine biotites, one cinnabar, fifteen iron rich clays, eight particles of iron oxides, eleven miniums
and sixteen particles of potassium alumina silicate with iron) are of potentially red colours. We explain the red colour of the sample by the intentional addition of these products during time, as a reinforcement of the faded red blood cells colour on this ancient linen time.

Keywords: Turin Shroud, Face Area, Blood Stains, Red Colours, Iron Oxides, Optical Microscopy, Scanning Electron Microscopy, Energy Dispersive X-Ray.