>>618820Flint is the archaeological term for chert, they are the same thing in actual composition.
It's usually referred to as flint if it's black and usually finer than most other cherts, the only acceptable way to use the term flint is if you're talking about the "flint" Europeans used or the chert Native Americans used.
Personally I think it's a stupid term and it just brings about confusion, like with you.
So the right is definitely not chert.
You'll know chert when you see it, if it's not black it will still have the same type of fracturing and feel to it.
The right mineral looks like pyrite to me, I'm feeling chalcopyrite but I'm not sure since I haven't looked at them in a long time.
If I was you I would either get more chert or split that piece into two.
Good luck anon.