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Identify · 3 min read

Is it a meteorite?

Canyon Diablo iron meteorite
Canyon Diablo iron meteorite
The short answer: Real meteorites are heavy, usually pull on a magnet, and have a thin dark crust with no bubbles. Holes and bubbles usually mean slag or volcanic rock.

  1. Start skeptical

    Most rocks sent to labs as meteorites are 'meteor-wrongs': industrial slag, hematite, magnetite or dark volcanic rock. A few checks rule most of them out.

  2. Test with a magnet

    Most meteorites contain iron-nickel metal, so a magnet sticks. No pull at all makes a meteorite unlikely.

  3. Feel the weight

    Meteorites are heavy for their size, much heavier than an ordinary rock.

  4. Look at the outside

    Look for a thin black or brown crust (fusion crust) and thumbprint-like dents (regmaglypts). Bubbles and holes throughout usually mean slag.

  5. Streak it

    A red-brown streak means hematite. A black streak from a strongly magnetic rock means magnetite. Most meteorites leave little or no streak.

    Hematite: red-brown streak, not a meteorite
    Hematite: red-brown streak, not a meteorite

  6. What to do if it passes

    Don't cut, polish or clean it with chemicals. Note exactly where you found it and contact a university meteorite lab or natural history museum. Many will look at photos first.

    Thumbprint dents on an iron meteorite (replica)
    Thumbprint dents on an iron meteorite (replica)
Tips
  • Check who owns the land: on some land a meteorite belongs to the landowner or the government.
Identify rocks on the spot with Rarestone for iPhone: point your camera at a rock and tap it. Get the app.

Photos: Canyon Diablo meteorite with a whistle-hole by subarcticmike, CC BY 2.0 · Hematite by Mustang Joe, CC0 · Block Island Meteorite (1/8-sized replica) (iron meteorite in the Block Island area on Mars) 1 by James St. John, CC BY 2.0. General information only: rules, safety and values vary, so check locally and ask an expert when it matters.