If you use cotton balls with some vaseline in them, you will get instant flame, no mucking around. Also the cheap firestarters at the supermarket which are budget brand are really good if you scrap a bit of into a pile on the top of it and hit that with a spark , instant flame. If you are talking about stuff you can find in or around the bush try the fluff off thistles or the tops off bullrush etc. Try dry manuka bark, and scrap the edge of your knife at 90 degrees to it and get a small fluffy pile of it. In my experience normally with a firesteel you should get flame as opposed to an ember, as with flint and steel, firesteel sparks are about 3000 degrees, much hotter than flint and teel sparks.
Go to the museum, if it is still open. They have some flint samples there that say where they where found. Flint seems seriously hard to get in NZ. I think that is why maori chose greenstone for a lot of their weapons etc. Maybe that is the reason the bow was not used here as suitable material for arrow heads was not available. I envy those you tube clips of guys saying ' you just go find a fallen tree, and look in the roots ' they make it seem easy. One thing I have noticed is that when people talk of finding flint in NZ it seems to be in limestone areas, do I have this right?
I am unaware of any really good flint sources in NZ. I've heard that there are some reasonable bits of flint-like rock around Clarence in the South Island, although it could be chert (whatever the difference is).
I had some pieces of flint or chert sent to me from a North Island source.... I think it was Raglan. They were just small nodules.
I understand that flint occurs in chalk... which is fairly closely related to limestone.
I've seen Maori tools made from what appears to be flint or chert. Only small things like drill points though.
I've also seen argillite flakes in the roots of a fallen tree at the site of an ancient Maori quarry. But argillite is quite a bit different to flint... much harder to flake.