Magnesium ribbon is an element and a metal. It is silver coloured, very light and really quite reactive. ... Hazards: Magnesium metal and alloys are highly flammable in their pure form when molten, as a powder, or in ribbon form. Burning or molten magnesium metal reacts violently with water.
It is used in pyrotechnics to produce certain firework mixtures or to ignite thermite reactions. Magnesium ribbon is one of the most common ways to ignite chemical reactions that require a higher temperature to ignite.