Antique Parchment Bookmark

Dear Donia,
I have an antique folded paper book/page marker that I'd like to know more about. Can you give me some details about what it's made of and how it's constructed?

bookmark

Q. Dear Donia,

I have, what I believe is, an antique folded paper book/page marker. It is embellished with fine painting and the paper is heavier than standard paper, almost waxy. I don't want to damage it but I would love to know how it is folded and how old you think it maybe. It may be from a teacher's book from the 1800s. Thank you, Liz

A. Dear Liz,

What a beautiful piece! The colors are still so vibrant. This does indeed look like a corner bookmark in a similar fashion of the modern origami ones you can find all over the internet. Yours, however, is much more carefully done!
 
This bookmark was made, not with paper, but with parchment. You can tell this from the visible hair follicles that look like little dots, easily seen on the back side of the bookmark.
 
Not being able to see the item in person, I have included a diagram below to show how I think it has gone together. Since it is parchment, I don't believe there would have been too many folds and layers like you get in the paper origami versions.
 
I hope this gives you some more insight into this great little piece!