McCrone's crystallographic work on polymorphism and its pharmaceutical applications played a central role in the subsequent development of the field.
[11] For more than thirty years McCrone edited and published The Microscope, an international quarterly journal of microscopy that had been established in 1937 by the British microscopist Arthur L. E.
[9] In the 1950s and 1960s, McCrone conducted extensive research on the microscopic characterization of polymorphs, which he defined as materials that are "different in crystal structure but identical in the liquid or vapor states".
The map's authenticity would have demonstrated the awareness of European catographers of a part of the American continent, before the voyages of Christopher Columbus.
McCrone, already reputed for his expertise in authenticating ancient documents and works of art, was asked by Yale to analyze the map in 1972.
In 1974, he published evidence that the ink of the map contained synthetic anatase (a form of titanium dioxide), a substance not used as a pigment until the 1920s.
[16][17] McCrone's work on the Vinland Map led to a protracted controversy, with other researchers continuing to argue for the document's authenticity and discounting the presence of anatase as insignificant.
With permission from the Archbishop of Turin, Cardinal Anastasio Ballestrero, STURP researchers conducted tests over a period of five days in October 1978, also using adhesive tape to obtain samples of the fibers from various parts on the Shroud's surface.
[10] Based on his microscopic and chemical analysis of the tape samples obtained by STURP, McCrone concluded that the image on the Shroud was painted with a dilute pigment of red ochre in a collagen tempera (i.e., gelatin) medium, using a technique similar to the grisaille employed in the 14th century by Simone Martini and other European artists.
McCrone also found that the "bloodstains" in the image had been highlighted with vermilion (a bright red pigment made from mercury sulfide), also in a collagen tempera medium.
Two other members of STURP, John Heller and Alan Adler, published their own analysis concluding that Shroud did show traces of blood.
[22] McCrone continued to defend his results and to insist that polarized light microscopy, in which he was the only expert among the original members of STURP, was the correct technique to apply to the study of the Shroud.
[25] In 2000, the American Chemical Society presented McCrone with its National Award in Analytical Chemistry for his work on the Shroud and for "his enduring patience for the defense of his methodologies".
[2] McCrone's work as a microscopist first attracted widespread public attention when he helped exonerate Lloyd Eldon Miller, a cabdriver who had been sentenced to death for the 1955 murder of an 8-year-old girl in Canton, Illinois.