Amazingly, the mineral turquoise has totally pseudomorphed an animal bone, turning it a light green color. On rare occasions animals and humans die in the vicinity of ore bodies, primarily copper, and their skeletons are replaced cell by cell by the minerals. A bone replacement is essentially a pseudomorph similar to Turquoise after Apatite, and this is a very educational example of how we ourselves are "mineralized." From the well-known pseudomorph collection of Ken Roberts. Specimens of this quality are very rare.