To identify whether a sample is a meteorite, you can consider the following aspects:
1. Surface molten crust: The meteorite has to pass through the dense atmosphere before it falls to the ground. The meteorite rubs against the atmosphere to generate high temperature during the landing process, causing its surface to melt and form a thin molten crust. Therefore, the surface of the newly landed meteorite has a black fusion crust with a thickness of about 1 mm.
2. Surface airmark: In addition, due to the interaction between the meteorite and the atmosphere, many airmarks will remain on the surface of the meteorite, just like the fingerprints of the fingers pressed down.
3. Internal metal: Iron meteorites and stony iron meteorites are composed of metallic iron. These irons have a high nickel content (5%-10%). There are also metal particles inside chondrites, and fine metal particles can be seen on the fresh fracture surface.
4. Magnetism: Because most meteorites contain iron, 95% of meteorites can be attracted by magnets.
5. Chondrites: Most meteorites are chondrites (90% of the total). These meteorites contain a large number of millimeter-sized silicate spheres called chondrites. Round chondrites can be seen on the fresh fracture surface of the chondrite.
6. Specific gravity: The specific gravity of iron meteorites is 8 g/cm3, which is much larger than that of ordinary rocks on the earth. Chondrites have a heavier specific gravity because they contain a small amount of metal.