My brother-in-law gave one of my kids a Razor brand sparking scooter last month. I've looked at the sparker thing and it appears to be a solid block of some soft metal. It isn't as brittle as sparker flints. It works really well at giving large trails of sparks along the sidewalk. I'm curious what the sparker is and if it could be used for simple home-made pyrotechnics (like sparkers from lighters can be: pull out the "flint" heat it in a flame until glowing, the spring from the lighter is good for holding the flint in a flame, then dash against a hard flame-proof surface: explosion of sparks).
------ presumed metal content