🤣 When you said item of jewellery I straight up was thinking about things like the knights templar or freemasons (their rings do look pretty cool), getting back to the point since there are already symbols for AB/ DL it would be beat to have something like the pin since it is already well known amongst the community.
(well some what, it's not really a good idea to come up with new stuff when there already is something that is accepted even if it is not fully known by the community)
I have thought about this before but as others have said in other threads the chance of randomly coming across someone from the community is pretty low and even then if you do happen to pass by them it's not likely that they would talk to you about it there and then if at all, I can understand the thought of maybe using it as a sign of pride or just to show your not afraid of who you are but other then that the only time I think this is useful is when doing a event or meet ups to make the start up better/ faster.
Side note: if I ever get time when I move out I might think about making some jewellery with the symbols for AB/ DL, would not be to hard to do things like that though now that I think about it I might have to look in to copyrights to see if that could come back to bite me.