Thanks guys! Martin - The mammoth ivory is quite nice to work with besides the nasty smell. If you ever decide to try it, be sure to use a good respirator as it's about as bad on your lungs as you can get. Working it reminds me of a good hard wood like desert ironwood or amboyna. Mammoth tooth on the other hand is some of the most difficult material you will ever encounter. The meteorite was really interesting to work with as well. It's cool to see it look like plain old steel while you're shaping / sanding and once you drop it into a nitric acid solution, you see the crystalline pattern re-appear almost immediately.