I found this on the floor my shop. It's possible I dragged it in from the street but it looks purposeful. Very sharp tip on it, a knurled grip on the top and a small amount of threaded part on the pin to insert into something. I'm just not sure what it fell out of - any ideas?
FYI - Don't know if this is your case but I had the scribe come loose on my Starrett and can't remember how but there is a way to re-tighten the fit (google it?).