Walter McCrone and the Shroud of Turin
It is possible that Walter McCrone found iron oxide and mercury, chemical components of paint pigments. But nowhere on the Shroud are there sufficient quantities of any pigment to form a visible image. Iron, for one thing, is a component of blood. The formation of iron oxide from some of the blood is possible. It would also be a byproduct of retting flax in iron rich water in the production of linen.
And just as miniscule particles of rust (iron oxide) is often found in dust, so too might mercuric sulphide be present in dust, particularly in churches and cathedrals with frescoed walls and ceilings and old paintings.
There is another possibility that might well explain the presence of paint particles on the Shroud. Many painted copies of the Shroud were produced. It was, after all, a revered relic. We know from history of a practice whereby artists would touch or lay their paintings on the Shroud for sanctification.
McCrone was the only scientist who actually examined fibers from the Shroud to make this claim. Every other scientist who has tested and analyzed the fibers disagrees with McCrone. It is significant that McCrone would not allow peer review of work.
Walter McCrone died July 10, 2002. He was 86. There is no question about the fact that he was a noted and honored microscopist. He received a bachelor's degree in chemistry in 1938 and a Ph.D. in organic chemistry in 1942 from Cornell. After becoming assistant chairman of the chemistry and chemical engineering at the Armour Research Foundation in Chicago, he founded the McCrone Research Institute. He also was editor and publisher of The Microscope, an international scientific journal and a distinguished member of the American Chemical Society. It was in 1978 that McCrone achieved world fame with his conclusion that the Shroud of Turin was painted during the Middle Ages.
But dozens of scientific tests and dozens of scientist have proven him wrong. See: The Shroud of Turin is not a Painting.
The Shroud of Turin may not have been Walter McCrone's only mistake. See: The Vinland Map
Much of the scientific material on this site is based on the work of Ray Rogers. Rogers, a chemist, is a science Fellow of the University of California, Los Alamos National Laboratory and a charter member of the Coalition for Excellence in Science Education. He has published many scientific papers in peer-reviewed journals and U.S. Government publications. In 1978, together with several other scientists, he was invited to personally examine the Shroud of Turin in Italy for several days. He collected numerous measurements and samples of fibers and particulate materials for further study. Rogers died March 8, 2005..
More information is available from links at Shroud of Turin Story and at A Forensic Science CSI - Pictures of Jesus on the Shroud of Turin