Meteorite or Earth Rock? The 7 Clues That Matter

Every dark, heavy rock sparks the same question: “Did this fall from space?” Most do not—but a few simple clues can help you decide whether it deserves expert attention.

1. Weight

Meteorites often feel unusually heavy because many contain iron and nickel. Weight alone is never proof.

2. Magnetism

A magnet can be useful, but many Earth rocks and industrial slag are magnetic too. Treat it as a clue, not a verdict.

3. Fusion crust

Fresh meteorites may show a thin, dark, matte outer skin formed during atmospheric entry. It is not usually bubbly or glassy.

4. Regmaglypts

Some iron meteorites have shallow thumbprint-like depressions. Random holes and gas bubbles are more typical of slag.

5. No quartz crystals

Visible quartz, abundant rounded vesicles, or a glittery surface usually point to an Earth rock.

6. Metal flecks

Cut surfaces of some meteorites reveal bright metal grains. Never cut a promising specimen before documenting it.

7. Get a real identification

Only laboratory work can confirm a meteorite. Local museums, universities, and recognized meteorite groups are better than social-media guesses.

Important: Do not use acid, heavy grinding, or destructive tests on a possible meteorite. Photograph it in daylight, record where it was found, and seek an expert opinion.

Tag someone who has a “space rock” on their shelf.

Further reading

• Meteorites Details