not only that but with the reproduction of marbles today and these bulgarian marbles surfacing trying to be germans.. a marble whether its a lattiacino solid core onionskin banded lutz any from the early days of the mid 1800's to the early 1900's of being more complex marbles...a pontil hasn't strayed from the orginal i haven't seen a pontil regular ground facet pinch look much different then each other... with that being said i use this to compare a marble to see if its real or repro... also studying pontil can help with seeing if a marble has been buffed polished or orginal