Image cropped for size from the original, posted in the antiques subreddit. I'll place the answer "below the fold" so you can ponder the item for a while before peeking... I assumed it was some sort of letter opener, but it's way more interesting. Here's the response by Redditor Qualmeister:
Folks, it is a parchment knife. The blade looks similar to the bleeding knives, but this is clearly writing desk equipment with a mother of pearl handle. One side of the knife is used to cut quills for writing and the other is for scraping dried ink off of documents, sort of an eraser.
Other guesses were that is was a "fleam" (bloodletting tool). Here's the Wikipedia entry for fleam.
You learn something every day.

It's very interesting, when I was in high school I was one of the library kids.
ReplyDeleteOur library actually had a knife of the same design. This would have been in the 1970s.
Handle was plain wood but the blade was exactly the same shape. I don't really know what it was intended to be used for at that time but they were still a thing.
?perhaps the librarians used it to slit open the pages of newly-published books when needed.
DeleteGot to love the internet. Turns out such knives are actually still available.
ReplyDeletehttps://www.schmedt.com/erasing-knife-with-wooden-handle-blade-length-60-mm/6165-001.
And still intended for the same purpose.