A magnet will stick to the meteorite if it contains much metal. You can use an ordinary refrigerator magnet to test this property. Most meteorites contain some iron-nickel metal and attract a magnet easily. So this test is helpful but not definitive. Lumps or fragments of human-made materials, ore rocks, slag (the byproduct of industrial processes) and the iron oxides magnetite and hematite, are also common all throughout the world and are frequently dense and metallic.
Iron meteorites are 3.5 times as heavy as ordinary Earth rocks of the same size, while stony meteorites are about 1.5 times as heavy. Density is how heavy a rock is for its size or compared with other rocks. It's not enough to say your rock is heavy. Unusual density is one of meteorites' more characteristic features. Ordinary chondrites and stony meteorites like the one at left have smooth surfaces or regmaglypts. Most iron meteorites, like the example at right, have well-developed regmaglypts all over their surface. The surface of a meteorite is generally very smooth and featureless, but often has shallow depressions and deep cavities resembling thumbprints in wet clay or Play-Doh. In the image below, the fusion crust is the thin, black coating on the outside of the meteorite. However, this crust weathers to a rusty brown color after several years of exposure on the Earth's surface and will eventually disappear altogether. It is often black and looks like an eggshell coating the rock.
This thin crust is called a fusion crust. When a meteorite falls through the Earth's atmosphere a very thin layer on the outer surface melts. Meteorites that have fallen recently have a black, glassy or ashy crust on their surface.
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