1 pound (16 ounces) EXTRA PETITE ridged dentalium shells
These are very, very petite! half inch to a little over an inch. My good source dried up, and these are all I can find. They are not the best quality. Believe me, I've been searching for better to no avail. These have not been sorted through, about 10% of the weight is crumbs and other shells.
They are very small, but pair them with those tiny 6mm or 8mm triangles I just got in, and I think they would be beautiful and dainty.