If you only read one post, read this one! This is the foundation of what Preservation Mammoths is all about. Protecting elephants and preserving mammoth tusks should go hand in hand.
I encounter a lot of mammoth tusks in my forays into the Klondike goldfields, literally tons of them! All are rough, most are just pieces, broken or partly rotten shards of the original tusk.
My mammoth tusks have survived Millennia entombed in the permafrost of subarctic Yukon. They have been preserved by permanently frozen ground for thousands, even tens of thousands, of years.