friction spark

friction spark is a mini toy to produce spark through friction. Use the sharp edge of the metal plate to scrape quickly along the cerium-stone. When small shavings of the cerium are removed quickly enough the heat generated by friction is enough to ignite those shavings, converting the metal to the oxide, i.e., the sparks are tiny pieces of burning metal. The sparking is due to cerium's low ignition temperature of between 150 and 180 °C. This gadget converts kinetic energy to thermal energy (heat) through frictional force.