How to identify a meteorite

Updated October 20, 2026. Based on the USGS, university meteorite labs and BLM policy; sources are at the end.

Only an expert can confirm it

Start with the fusion crust, a thin, dark skin that forms when the outside melts on the way through the atmosphere: Washington University’s meteorite lab says that without one there is no reason to suspect a meteorite. Then try a magnet and a streak test on unglazed ceramic, and look for quartz or bubbles, which rule a meteorite out. Even if everything fits, only an expert who examines the rock itself can confirm it.

Fusion crust: Thin, dark skin, rarely over 1–2 mm
Magnet: Most meteorites attract one, but so do many Earth rocks
Streak: None, or faint gray, on unglazed ceramic
Rules it out: Visible quartz, gas bubbles, a red or black streak

Seven checks

The first column is the USGS checklist; the caveats come mostly from Washington University in St. Louis.

Check	Points to a meteorite	But
Fusion crust	A thin, dark crust where the outside melted on the way through the atmosphere	Rarely more than 1–2 mm thick. Desert varnish and dark, polished rocks look similar, but they are the same color inside.
Magnet	Most meteorites attract a magnet; a stony one may only pull a magnet hung on a string	Many Earth rocks and slag attract a magnet too. Use a cheap fridge magnet, not a strong neodymium one.
Streak	No streak on unglazed ceramic, or a faint gray one if pressed hard	No streak does not prove a meteorite: igneous Earth rocks leave none either.
Weight	Usually heavy for its size, because of metallic iron	A weak sign: some Earth rocks are denser, and most “heavy” finds are iron-oxide concretions.
Shape	Iron meteorites are rarely rounded and often have thumbprint-like pits called regmaglypts	Not all meteorites have them, and Earth processes make similar dimples.
Quartz	No visible light-colored crystals such as quartz	A rock that cuts a deep scratch in glass is not a meteorite.
Bubbles	No gas bubbles	Volcanic rock and slag are often bubbly. Very few stony meteorites have small, sparse holes; iron ones sometimes have holes.

A dark brown-black meteorite fragment with a thin dark crust and a small light-colored chip — A piece of the Park Forest meteorite, which fell near Chicago in 2003: the dark fusion crust, with lighter stone where it is chipped. Photo: James St. John, CC BY 2.0.

Doing the tests

Fusion crust: wet the rock. The crust is almost always darker than the wet interior; carbonaceous chondrites are the exception.
Magnet: a cheap ceramic fridge magnet. Phone apps that measure magnetism are useless for this.
Streak: scrape the rock on the unglazed back of a white tile or the ring under a coffee mug. Red or red-brown means hematite; dark gray to black means magnetite.
Metal pieces: metal that does not strongly attract a ceramic magnet is not a meteorite. Metal that does needs a lab test for iron, nickel and other elements.

Common meteorwrongs

Iron-oxide nodules and concretions: the most common meteorwrong sent to Washington University.
Hematite and magnetite: two common look-alikes, according to Arizona State University. They leave a red or dark streak.
Slag: an industrial by-product, often magnetic and bubbly, and common because it is used as fill for roads and train tracks.

Can an app or a photo tell?

No. Washington University in St. Louis says AI image apps cannot identify meteorites, and that image searches are nearly always wrong when they suggest one. The USGS says rocks and minerals are extremely difficult to identify from photographs, and Arizona State University says online testing alone cannot conclusively identify a meteorite.

Where to get it checked

Local experts: the USGS does not verify meteorites. It suggests your state geological survey, a natural science museum, a college or university geology department, a rock shop, or a gem and mineral club.
Portland State University: its Cascadia Meteorite Laboratory asks you to read its identification pages, then email a couple of in-focus photos. It does not want samples mailed without permission, phone calls or visits. Its instructions.
Don’t mail samples to Arizona State University’s meteorite center, which stopped public identification in 2010 and will not return specimens. The University of New Mexico’s Meteorite Museum does not inspect suspected meteorites.

Can you keep it?

BLM land: a 2012 BLM policy allows casual collecting without a permit, up to what you can easily hand-carry and 10 pounds a year, surface only, metal detectors allowed, for personal use. Its header shows a 2013 expiry, and we found no replacement, though BLM Arizona’s rockhounding brochure repeats the 10-pound limit. Check with the BLM.
No casual collecting on National Park Service, Bureau of Reclamation or Fish and Wildlife Service land.
Private land: according to the BLM, courts have long held that a meteorite belongs to the owner of the land surface where it is found.
National forests: we found no rule; ask the forest.

Keep a log of your finds

The Capyhound app will save each find with its photo, place and date, even with no signal.

Questions

How can I tell if a rock is a meteorite?

Signs that point toward one, according to the USGS: heavy for its size, attracts a magnet, a thin dark fusion crust, and thumbprint-like pits on iron meteorites. Signs against: visible quartz, gas bubbles, and a black or red streak on unglazed ceramic. Even then, only an expert who examines the rock can confirm it.

If a magnet sticks, is it a meteorite?

Not necessarily. Most meteorites attract a magnet, but so do magnetite-rich Earth rocks and slag. Washington University in St. Louis suggests a cheap fridge magnet, not a neodymium one, which attracts many Earth rocks.

What is the streak test?

Scrape the rock on the unglazed back of a white tile or the ring under a coffee mug. Meteorites leave no streak, or a faint gray one. A red or red-brown streak means hematite; dark gray to black means magnetite. No streak does not prove a meteorite.

What is a fusion crust?

A thin, dark skin that forms when the outside of a meteorite melts on its way through the atmosphere. It is rarely more than 1–2 mm thick.

Can an app or a photo identify a meteorite?

No. Washington University in St. Louis says AI image apps cannot identify meteorites, and the USGS says rocks are extremely difficult to identify from photographs. An expert needs to examine the rock itself.

Where can I get a suspected meteorite checked?

The USGS suggests your state geological survey, a natural science museum, a university geology department, a rock shop or a gem and mineral club. Arizona State University’s meteorite center stopped public identification in 2010, and the University of New Mexico does not inspect suspected meteorites. Portland State’s lab reviews photos sent by email first and accepts samples only with permission.

Can I keep a meteorite I find on public land?

A 2012 BLM policy allows casual collecting on open BLM land without a permit: up to 10 pounds per person per year, surface collecting only, metal detectors allowed, for personal use only. It does not allow casual collecting on National Park Service, Bureau of Reclamation or Fish and Wildlife Service land. The policy document shows a 2013 expiry date, so check with the BLM before you rely on it.

Sources

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