Sorry, just saw this. I went looking for all the references to Mat’s dagger. It’s described differently almost every time in the first 3 books.
In the Dragon Reborn in the chapter Secrets, Elayne describes it as “curved dagger in a golden sheath, a Ruby the size of a pigeon’s egg capping the...
Re: the dagger - just cause I am doing a reread at the moment, the dagger in the teaser is actually the way it’s described in the book with the Ruby set into the hilt.