Is It a Meteorite? How to Check a Suspicious Rock

A quick checklist

ASU's identification page offers a five-question screen. A "no" to any question suggests the specimen is probably not a meteorite, and a "yes" to all five does not confirm one. The list below adds a few checks from the U.S. Geological Survey (USGS).

• [ ] The surface is smooth and black or brown, with no holes or bubbles.
• [ ] The rock is solid and compact, and heavy for its size compared with an ordinary rock.
• [ ] A magnet is attracted to it. For stony types, try a magnet hung on a string.
• [ ] It is entirely metal, or it shows tiny metallic flecks on every cut, broken or polished surface.
• [ ] Scraped on unglazed ceramic, such as the bare ring on the bottom of a coffee mug, it leaves no gray-black or red-brown streak.
• [ ] No quartz or other light-colored crystals are visible.
• [ ] If it is a recent fall, the outside may be black and shiny. Iron types may show thumbprint-like dents.

Treat the list as a screen, not a verdict. A rock that passes every line can still be an Earth rock, and a real meteorite that has weathered for years can fail a line or two.

Test by test: what each clue means

Fusion crust. When a meteorite falls, heat from the passage through the atmosphere cooks its surface into a thin crust. ASU says a freshly fallen meteorite looks black and shiny, and that over time the crust wears away and the surface turns rusty brown. ASU's guide to identifying meteorites calls fusion crust the first hint that a rock might be a meteorite. Meteorites can also carry thumbprint-like dents called regmaglypts and thin flow lines. A missing crust does not rule a rock out, but a convincing one is a good sign.

Weight. ASU says meteorites are heavier than Earth rocks of the same size, because of their nickel-iron content. The USGS describes them as quite heavy for their size. Pick the rock up and compare it with a stone of similar size.

Magnet. This is the test people trust most and should trust least. ASU says most meteorites are attracted to a magnet, but also that a magnet is not a reliable test. Weathered ordinary chondrites are often only weakly magnetic because their iron has oxidized, and both slag and magnetite are highly magnetic. ASU's identification guide adds that only iron-rich meteorites, such as the iron and stony-iron families in the main types of meteorites, reliably attract magnets, and that lunar meteorites, made only of rocky minerals, will not.

Streak. Scrape a corner of the rock across unglazed ceramic. ASU says hematite leaves a red-brown streak and magnetite a gray-black one, and a meteorite should not leave either. Weathered ordinary chondrites can leave a brownish-orange mark, according to ASU, while a rock that leaves no streak at all may be slag.

Bubbles and crystals. The USGS says meteorites lack bubbles, which are common in volcanic rock and slag, and that they do not contain quartz, a common light-colored crystal in Earth's crust.

Nickel. Meteoritic metal carries a lot of nickel. Confirming it needs further testing, and the NASA Night Sky Network warns that the chemical test is not suitable for general audiences or children.

Common look-alikes (meteorwrongs)

ASU calls Earth rocks that get mistaken for meteorites "meteorwrongs." A handful account for most mistakes.

A rock is a meteorite only if it came from space and reached the ground, as meteor, meteoroid and meteorite explains, so the first four rows of the table do not qualify. ASU says slag can turn up almost anywhere, even in what looks like the middle of nowhere, and that magnetite and hematite occur commonly across the United States. That is one reason ASU says a magnet alone is not a reliable test.

Who can confirm a find

The USGS does not verify meteorites. It says rocks and minerals must be examined in person, from all sides, because photos make identification very difficult. It suggests taking the specimen to a local source, such as a state geological survey, a natural science museum, or a college or university with a geology department.

ASU's public identification program is closed. Its guidance says specimens sent to the program are no longer accepted, that the program was suspended in 2010, and that people should not send a specimen to the center. As of November 2026, that is what the page says. Check before mailing a rock anywhere.

Practical steps help whoever examines it. Note where you found the rock before you move it, keep it in a clean bag, and take photos of every side. If you saw a bright fireball just before finding it, the fireball report checklist explains what to record, since the date and direction of the fall can narrow a search. Real meteorites matter beyond the rock itself. Scientists connect meteorites to their parent asteroids with several methods, which are described in how scientists learn what asteroids are made of.

Common mistakes and myths

• "The magnet stuck, so it is a meteorite." Slag and magnetite are strongly magnetic too, and a weathered meteorite may barely respond.
• "It has a black shell, so it has a fusion crust." Desert varnish and slag can look similar, and ASU says slag often shows flow marks and bubbles that mimic a melted surface.
• "Meteorites are round, smooth lumps." The USGS says iron-nickel meteorites are rarely rounded, and they often have small pits called regmaglypts.
• "Meteorites are easy to find and worth a lot." The NASA Night Sky Network lists both as misconceptions. Most rocks sent in turn out to be Earth rocks.
• "A photo is enough for an expert." The USGS says photos make identification very difficult, and in-person examination is needed.

Frequently asked questions

Does a magnet prove a rock is a meteorite?

No. Most meteorites attract a magnet, but so do slag and magnetite, and weathered meteorites can respond only weakly. A magnet helps screen a rock, and it never confirms one.

What does a fusion crust look like?

On a fresh fall it is black and shiny. ASU says it wears away with time and the surface turns rusty brown, so older finds often lack a crust.

Where can I get a rock checked?

Try your state geological survey, a natural science museum or the geology department of a local college or university. The USGS suggests these sources and says it does not verify meteorites itself.

How often is a suspicious rock really a meteorite?

Rarely. ASU says fewer than 1% of the rocks sent to its center were meteorites, and more than 90% of the finds people described to it turned out to be terrestrial.