White Particles on the Turin Shroud: Optical Microscopy Studies and SEM-EDX Analyses

We have explored by optical microscopy and scanning electron microscopy coupled with energy dispersive X-ray about one hundred and fifty particles of white pigments located in a sample of the Face area of the Turin Shroud. Twenty-one of them are micro-fragments of marble. Thirty-two of them are particles of different Coccolith species of chalk. More than fifty of them are ceruse micro-plaques and four are ceruse plaques (yellow in colour); about sixty-four are ceruse micro-balls. The white of zinc is represented by only one particle. There is one paint film of titanium dioxide and nine other micro-plaques, micro-scales and micro-balls of this pigment. All these particles contribute significantly to the bleaching of the Turin Shroud.