Don't feel like you HAVE to use a rare piece of stone for flint and steel fire making. Any rock with a sharp edge and denser nature than the steel will work just fine. This stone could be flint, chert, agate, jasper, quartz or anything else that is harder than your steel striker. The char can also be made from many different materials as well, so long as it is some form of partially burned, plant based material for catching and feeding a spark. Cotton and linen fabric were traditional American frontier char cloth materials. However, most flammable plant fibers, tinder, some shelf fungi and punky, rotten wood can be turned into "char cloth."