Stony-iron meteorite
A stony-iron meteorite is made of roughly equal amounts of metal and rocky minerals.
Stony-iron meteorites are a mixture of iron-nickel metal and rock. They are the rarest of the three main kinds, making up only around one in a hundred falls, and many collectors think they are the most beautiful.
There are two main types. Pallasites contain glassy green or golden crystals of a mineral called olivine set in shining metal. When thin slices are polished, light can shine through the crystals like stained glass. The pallasite Esquel, found in Argentina, is famous for this. Mesosiderites are messier: broken pieces of rock and metal jumbled together, probably by violent collisions between asteroids. Vaca Muerta from Chile's Atacama Desert is a well-known example.
Scientists study stony-irons to learn about the insides of asteroids and the crashes that shaped them. You can recognise them by their weight and their strong pull on a magnet, and by a patchy mix of shiny metal and stony areas on a cut face. Their metal can rust quickly, so they are best stored somewhere dry. Leave the cutting and polishing to experts.
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Level: Beginner Ages 7 and up