Samples were submitted to the Geological and Nuclear Sciences Crown Research Institute in Wellington, New Zealand for testing. However, geologists at the government institute concluded that the samples were volcanic rock and not petrified wood.[17] Shroud of Turin: Critics insist that the linen cloth contains a painting of Jesus made in the Middle Ages. Others maintain that the image was formed by an energetic process that darkened the fibres of the shroud at the moment of resurrection.