Firestones, also known as flintstones, are natural rocks used to start fires. Other synonyms for firestones include ferro rods, firesteel, and sparking rocks. These handy tools are essential for outdoor enthusiasts, survivalists, and preppers. A ferro rod is a man-made tool that contains a flint-like material, capable of producing sparks when scraped with a metal striker. Firesteel refers to a specific type of ferro rod that is often coated in a protective layer to prevent rust buildup. Sparking rocks, or quartzite, are natural stones that create a spark when struck against a harder material, such as steel. Regardless of the term used, firestones are a valuable asset for anyone looking to start a fire without relying on matches or lighters.