How to Tell If a Rock Is a Meteorite: 7 Tests You Can Do at Home

You found a heavy, weird-looking rock and now you're wondering: could this be from outer space? It's a fair question. Thousands of meteorites land on Earth every year, and most go unrecovered. But here's the reality check: about 99% of rocks people think are meteorites turn out to be ordinary Earth rocks. These imposters are affectionately called "meteor-wrongs."

So how do you tell the difference? There are several reliable tests you can do at home, and they don't require a geology degree or expensive equipment. Let's walk through them.

What Are Meteorites Made Of?

Before testing, it helps to understand what meteorites actually are. They're chunks of rock or metal (or both) that survived their fiery passage through Earth's atmosphere. There are three main types:

• Iron meteorites: Almost entirely nickel-iron metal. Very heavy, magnetic, and distinctive.
• Stony meteorites: The most common type. Made of silicate minerals with varying amounts of metal. Subdivided into chondrites (with small round grains called chondrules) and achondrites (without).
• Stony-iron meteorites: A mix of metal and silicate minerals. The pallasites, with olivine crystals embedded in metal, are among the most beautiful natural objects on Earth.

Test 1: The Magnet Test

This is the easiest first test. Almost all meteorites are magnetic because they contain nickel-iron metal. Grab a strong magnet (a rare-earth neodymium magnet works best) and hold it near your rock.

If the magnet sticks strongly, that's a good sign — but it's not conclusive. Many Earth rocks are also magnetic, including magnetite, hematite, and some basalts. If the magnet doesn't stick at all, your rock is almost certainly not a meteorite (with very rare exceptions like some lunar and Martian meteorites).

Verdict: Magnetic = might be a meteorite. Not magnetic = almost certainly not.

Test 2: Check the Density (Weight Test)

Meteorites are dense. Noticeably heavier than most Earth rocks of the same size. Iron meteorites are extremely dense (about 7-8 g/cm³), and even stony meteorites are denser than typical rocks (about 3-3.5 g/cm³ vs. 2.5-2.8 for average Earth rock).

Pick up your suspect rock. Does it feel surprisingly heavy for its size? If it feels about the same weight as similar-sized rocks around it, it's probably not a meteorite.

For a more precise test, you can measure specific gravity at home: weigh the rock on a kitchen scale, then weigh it suspended in water (the difference tells you the volume, and weight/volume gives you density). A density above 3.0 g/cm³ is promising.

Test 3: Look for a Fusion Crust

When a meteoroid enters the atmosphere at tens of thousands of miles per hour, the exterior melts and forms a thin, dark coating called a fusion crust. On a fresh fall, this crust is typically dark black or very dark brown, with a matte to slightly glossy surface.

Over time, weathering can erode or alter the fusion crust, making it harder to identify on older finds. But if you see a thin, dark, paint-like coating on part or all of the rock — especially if the interior (visible where the crust is chipped) is a different color — that's a strong indicator.

What it's NOT: A thick, bubbly, or glassy coating is more likely slag (waste from metal smelting) than a meteorite. Real fusion crust is thin and relatively uniform.

Test 4: Check for Regmaglypts (Thumbprints)

Many meteorites have shallow, rounded depressions on their surface that look like someone pressed their thumb into clay. These are called regmaglypts, and they form during atmospheric entry as the surface material ablates (melts away) unevenly.

Not all meteorites have obvious regmaglypts, but when present, they're a strong identifier. Earth rocks rarely have this specific pattern of smooth, overlapping depressions.

Test 5: Look Inside (The Streak and Cut Test)

If possible, examine a fresh surface of the rock. You can file a small corner or look at a naturally broken surface. Here's what to look for:

• Metal flecks: Most stony meteorites contain visible specks of shiny metal (nickel-iron) scattered throughout the interior. This is rare in Earth rocks.
• Chondrules: Small, round, grain-like structures visible in the matrix. These are a defining feature of chondrite meteorites and don't appear in terrestrial rocks.
• No holes or bubbles: Meteorites are NOT porous or bubbly. If your rock has holes, vesicles, or a pumice-like texture, it's volcanic, not extraterrestrial.

Also try the streak test: drag the rock across an unglazed ceramic tile. Meteorites typically leave no streak or a very faint brownish streak. A strong red, black, or colored streak indicates a terrestrial mineral.

Test 6: The Nickel Test

This is one of the most definitive home tests. All meteorites contain nickel (typically 5-25% in the metal phase), while most terrestrial iron sources contain little to no nickel. If your rock is metallic, you can buy a nickel test kit (used for jewelry testing) to check for nickel content. A positive result strongly supports a meteorite identification.

For a quick preliminary check, you can also use Rock Identifier to snap a photo of your suspect rock. While confirming a meteorite definitively requires lab analysis, the app can help you identify common "meteor-wrongs" and assess whether further testing is worthwhile.

Common Meteor-Wrongs

These are the rocks most commonly mistaken for meteorites:

• Slag: Industrial waste from smelting. Often heavy, metallic, and dark. Usually has bubbly or glassy texture — meteorites don't.
• Magnetite: A naturally magnetic iron oxide mineral. Very dense and magnetic like a meteorite, but has a black streak (meteorites don't).
• Hematite: Dense iron oxide with a red-brown streak. Can look dark and heavy like a meteorite.
• Iron ore nodules: Natural iron-rich rocks that are heavy and magnetic. Common in many areas.
• Volcanic rock (basalt): Dark, dense rock. Sometimes mildly magnetic. But it's much lighter than iron meteorites and lacks metal flecks inside.
• Concretions: Rounded sedimentary formations that look unusual but are just cemented sediment.

Signs It's Probably NOT a Meteorite

Your rock is almost certainly terrestrial if:

• It has holes, bubbles, or vesicles (meteorites are solid)
• It has visible quartz or crystal layers
• It leaves a colored streak on ceramic
• It's not magnetic at all
• It has a layered or banded structure
• It's lighter than expected for its size
• It has a glassy, bubbly, or slaggy texture

What to Do If Your Rock Passes the Tests

If your suspect rock is magnetic, dense, potentially has a fusion crust, shows metal flecks inside, and lacks holes — congratulations, you have a genuine candidate! Here's your next steps:

• Don't clean it aggressively. Gentle brushing is okay, but don't scrub, polish, or acid-wash it.
• Document the find location. GPS coordinates, photos in situ (where it was found), and notes about the surrounding area are all valuable.
• Contact a meteorite expert. University geology departments, natural history museums, and the Meteoritical Society can help with identification.
• Get a classification. Official classification requires a sample to be sent to an approved lab. This establishes the meteorite type and makes it scientifically recognized.

What Are Meteorites Worth?

Meteorite values vary enormously:

• Common chondrites: $0.50 to $3 per gram
• Iron meteorites: $1 to $5 per gram
• Rare types (pallasites, lunar, Martian): $50 to $1,000+ per gram
• Witnessed falls: Premium prices for meteorites seen falling and recovered quickly

A typical fist-sized meteorite (200-300 grams) of a common type might be worth $100 to $500. Rare types or aesthetically striking specimens can be worth thousands.

Whether your mystery rock turns out to be from space or just an interesting Earth rock, the investigation is half the fun. Use Rock Identifier as your first step — snap a photo and see what our AI makes of it. Then break out the magnets and start testing!