Personally I am going towards the opinion it is tridacna, although that would be -I think; though am not an expert on Visayan/moro- quite more special n interesting than bone/ivory.
Thor; 'The problem with
onomatopoeia is the . . . . '
I like mine hot and with some ketchup pls?
Whatever the material is bone or tridacna I would really leave it and not burn or wax it; its looking lovely as it is n its just a matter of time to know its real material.
Actually tridacna is/can be quite breakable material and not much used for large or long items. If it falls on a hard floor it will break. I only know this material from New Guinea shellmoney rings (socalled 'yua') and have seen only few tridacna Indonesian kerishandles.