Found on a beach in Yorkshire that has holes in and feels like a mix between stone and plastic. Any ideas ?

Found on a beach in Yorkshire that has holes in and feels like a mix between stone and plastic. Any ideas ?

Answer: It’s a Victorian’s toothbrush.
Bone toothbrushes, bristles missing. (These would have decayed in the ground.) Toothbrushes were a luxury. Poorer people would have cleaned their teeth with a stick or marshmallow root or rag and soot.