“My girlfriend brought it when we moved in. What is this?”
That’s a grave marker. Not sure what the police might do unless you think there’s a grave on your property that you’ve uncovered. Worth a shot. Alternately perhaps an office of public health might be able to figure it out. In any case, it would be nice to ensure that a grave wasn’t dug up by a developer and the remains and someone just dumped as fill. kludge6730 / Reddit