Crystallized dinosaur

Cross section of a dinosaur bone at 15× magnification. The bone (blue), from an unknown species, is about the size of a roll of duct tape and was found in the Morrison Formation on the Colorado Plateau, where fossils are common. The iron oxide (red) in the quartz-filled (white) sample could be part of the marrow or spongy bone, but Barker says “it could also be a tree root that grew and decomposed over the millions and millions of years it takes before the actual specimen becomes fossilized.”