I know. It just looks weirdly familiar to me, too. Like I've seen it on another show.

(I just know that Jonathan's getting some mesmerism done to him at the end of the fanfic I'm doing, and if nobody can figure it out, mysterious artifact on a chain sounds as good as anything else.

Edit: Oh! It looks a little like a large coin with a hole in the middle that I've seen before, with a watch chain put on it, doesn't it? I don't know what particular origin that sort of coin would be.

Edit 2: These look very close They’re from around 1820-1850, Chinese, from (according to the link) “the reign of the Dao Guang emperor,” so Van Helsing would be likely to have picked up one in his travels if that’s what it is.