Magnesium is a highly reactive metal that can be ignited by creating friction with another rough surface, such as a knife or a rock. It’s commonly used in emergency fire starting kits because it’s lightweight and easy to carry. However, it’s important to note that magnesium should only be used in emergencies and not as a primary method of starting fires. In addition, it can produce a bright white light which can be blinding, so it’s recommended to use caution when using magnesium fire starters.