mischmetal

thumb|A handful of mischmetal pellets

Mischmetal (from – "mixed metal") is an alloy of rare-earth elements. It is also called cerium mischmetal, or rare-earth mischmetal. A typical composition includes approximately 55% cerium, 25% lanthanum, and 15~18% neodymium, with traces of other rare earth metals totaling 95% lanthanides, plus 5% iron. Its most common use is in the pyrophoric ferrocerium "flint" ignition device of many lighters and torches. Because an alloy of only rare-earth elements would be too soft to give good sparks, it is blended with iron oxide and magnesium oxide to form a harder material known as ferrocerium. In chemical formulae it is commonly abbreviated as Mm, e.g. MmNi5.