It is an interesting question as to whether mammoth ivory is fossilised or not. From most of the websites that sell it I get the idea that it has been gathered from frozen siberian permafrost, so rather than being fossilised it has been kept in a kind of natural deep-freeze.

Some shows I saw on TV that extracted the animals said that the meat could still be eaten, and you could see that the skin and hair were almost as when the creatures were alive.

Regards,
Neil