Wheel-lock and flint-lock are two different animals. The wheel lock used iron pyrite, not flint, for one thing.
The mineral pyrite or iron pyrite, also known as fool’s gold, is an iron sulfide with the chemical formula FeS2 (iron (II) disulfide). We used to find that stuff out here. Had to go up in the FlintHills out here east and north of the Vermillion River to find flint chards. Would like to build a wheel lock sometime.