My wife and I each carry a Kershaw blackout as edc. We have, everyday, for almost a year now. I can't tell you what the clips are blackened with, but, they show 0% wear or scratching. We both wear tight jeans, we both wear rings on both hands.
On the other hand, I owned a Camillus Cuda EDC (brand) for a couple of weeks. It had a blackened clip that showed scratching and wear in a couple of days, notably, gold colored, as if the rings I wear was harder than the clip's finish. And I don't mean that the rings left just gold-color, You could see the physical gouging, feel them with your nail.
Go figure, and, YMMV
WayLander