as I mentioned in the video, I have had the chance to evaluate quartz and quartzite now for a good bit and have come to appreciate this versatile rock. It may not be as durable at the edge as flint but from what I have seen it is more plentiful across the planet. It fractures like flint when spalled and develops the sharp edges we love from driving sparks off for 'flint' and steel. I have found it is as varied as most other rocks and comes in so many subtle variates, colours and the way it acts under the striker. I would never feel at a disadvantage if I only had quartz or quartzite available to me, I would just recognize its inherent weaknesses and work with the stone to maximize its usefulness. What I suggest is to use bigger stones to start with, because you will burn through the edge quicker if you start with a larger stone you can chip out the edge and then spall it small and continue to use the smaller stones.
