And there is no scientific evidence that the famous skull has properties different from other crystalline quartz. Attracting more pilgrims than any other Catholic shrine except the Vatican, the image is widely reproduced in the form of icons, religions medals, neon signs, even tattoos. Due in part to confusion of the image with that of their own Virgin goddess, Tonantzin, the Aztecs were soon converted to Catholicism. In fact, if the image were scientifically inexplicable it would be because independent scientists are not permitted to examine it. However, photographic enlargements show obvious signs of artistry, including some places where paint has obscured the cloth's weave and others where it has cracked.
Infrared photos reveal preparatory sketch lines beneath the paint.
Also, the image copies traditional Spanish portraits of Mary, and there is a report from an investigation of 1556 that the work was done by an Indian painter named Marcos. Investigation, however, soon showed the animals were not drained of blood, and stakeouts invariably yielded nothing more exotic than wild dogs. Despite folktales of his prowess, however, it appears that Arigo simply performed primitive surgeries like lancing boils or removing cysts, while prescribing antibiotics and mumbo-jumbo remedies. Common also to the Philippines, such effects are fraudulently produced by sleight of hand using animal tissue and blood. For example, in 1991 a total solar eclipse attracted numerous skywatchers whose camcorders captured luminous UFOs hovering overhead.