It’s a glass dip pen. 

Easier to use than quills and fountain pens,

but they have that cool scratch feel as they’re drawn across the paper.

They are available in sets with lots of nice ink colors.

Here’s illustrator Peter Draws showing what it’s like.

If you’re used to a responsive tip and pressure sensitive ink delivery, this can take some time to acclimate, but it can give surprising results in the right hands.