There is an adage that some artists use found pieces to make their art.
They create using what they find around. I do that everyday I guess because rocks are everywhere and I ‘turn boulders into bears’.
But truly found pieces would be the Walrus that needs some tusks. Ivory is illegal, stone tusks just wouldn’t look right.
There goes my wife’s carving set. The handles look perfect as tusks. They needed a little roughing up but , take the pieces where you find them