I'll make them out of anything that a customer wants with the exception of fossilized Stellar Sea Cow bone. I made one knife with it and had a bad allergic reaction to the dust from grinding and polishing it. I broke out in a rash and itched like crazy for a couple of days I've never used elephant Ivory either but that's more of a moral thing since there is no way for me to tell how old the ivory is and I don't want to add to the poaching problem that the elephants already endure. I love the look of fossil Mammoth Ivory though and since they have been extinct for around 10,000 years using it can't hurt anything. I've even used Walrus Oosik (it's the bone from their penis ) I'll make recommendations when asked, depending on what the knife is going to be used for. Thanks to all for the kind comments.