Science, Maths & Technology
Strange coloured teeth; strange coloured bones
...change appears to have been brought about by heating following the incorporation of the metal manganese (oxidizing it to the Mn5+ valence state, which forms blue-coloured salts). This mechanism also appears to explain the origins of turquoise-like ivory (odontolite) acquired from deposits of fossilized mastodon teeth and used decoratively in the Middle Ages. You can read...