How to tell if the rock you found is a meteorite

Photo: DenVDen (Shutterstock)

Have you found a strange rock while hiking and thought, “I bet this is from outer space!” I have. Unfortunately, it’s definitely not a meteorite. As cool (and lucrative) as it would be to hazard the remains of a meteor that survived its journey through the atmosphere to hit Earth, finding a genuine space rock is a chance to win the lottery. People thinking they discovered that a meteorite is as common as socks. Still, it can’t hurt to check, so here’s a simple guide to whether this cool-looking piece is from outer space or just some dumb, boring Earth rock.

Meteorites are rare

Research from the University of Manchester and Imperial College suggests that around 17,000 meteorites weighing between 50 grams and 10 kilos hit the Earth each year, which might seem like a lot, but we’re talking about tiny randomly scattered objects. all over the planet. Most of them fall into the oceans, and most of those that hit land are small and unassuming, so the chance you encounter a random meteorite and noticing that he is thin—only about 1,800 meteorites have been found in the United States over the past two centuries. You’re better off looking for diamonds, gold, and emeralds, all of which are more abundant than meteorites.

The best spots to hunt meteorites

Despite their rarity, people still occasionally find meteorites, but usually they’re looking in the right places. The best place to hunt space junk is Antarctica. Meteorites don’t fall there any more often than elsewhere, but the dark bits of rock and metal are more visible on the white ground. Other places meteor hunters might consider are the Mojave Desert in California and the Sahara in Africa. Think dark pieces on a light background.

How to know if you have found a meteorite

If you manage to spot a rock that looks out of place while hiking in the desert, don’t get too excited. It’s probably not a meteorite yet. Here are some characteristics of meteors and meteor mischief to help you determine if you’ve been extremely lucky.


Real meteorites tend to have these characteristics:

  • fusion crust: Meteorites are usually covered in an ashy black layer of molten rock caused by the intense heat generated as they pass through the atmosphere. Although the color may change to a rusty brown after years on Earth, the absence of anything resembling a fusion crust almost always means it’s not a meteor.
  • Density: Meteorites are heavier than other rocks of their size. Iron meteorites are 3.5 times heavier than a typical Earth rock. Stony meteorites are about one and a half times heavier. But a piece of slag, a by-product of industry, is also heavy, and way more common than a meteorite.
  • Regmaglypts: Meteorites usually have smooth surfaces, but they are often covered in regmaglypts, small depressions that look like someone has stuck their thumb in wet clay.
  • Magnetism: Most meteorites contain iron-nickel and attract a magnet. However, many rocks on Earth do this too. Both magnetite and hematite are common, heavier than other rocks, magnetic and can look like meteorites, so it’s not an easy process.
  • Without streaks: If you rub most regular rocks against the unglazed side of a piece of kitchen or bathroom tile, it will leave a streak. Meteorites generally do not.


If your rock has any of these characteristics, it’s probably not a meteor:

  • Roundness: Meteors are almost never round. They are irregular in shape, as earth forces such as erosion have not affected them.
  • Bubbles or holes: Earth rocks often contain bubbles or holes. Meteorites don’t.
  • Radioactive or hot: Meteorites are almost always cold when they hit the Earth. They don’t light a fire on the ground. Travel through the atmosphere is rapid and does not heat the interior of the rock. They are also not radioactive, so your Geiger counter is of no use.

So now do i have a meteorite?

If your rock has passed all of these tests, it may be a meteorite, but it probably isn’t. Many terrestrial objects can look like meteorites. Slag is probably the most common meteor, but there are also basalt, iron ore, coal, bits of asphalt, charcoal briquettes, etc. Basically anything can be (and probably has been) mistaken for a meteorite by someone.

It’s hard to get a professional to take care of your little rock

As hard as it is to find a meteor, it may be harder to find a geologist who will help you identify it, so don’t take it to the local university or knock on the door of the geology department. . Geologists have to see her with people coming to ask questions about the strange rock they found. look at this incredibly grumpy rant from lunar geochemist Randy L. Korotev of Washington University in St. Louis who begins: “In 2022, I was contacted 5,905 times by 2,095 different people from 89 countries… Almost all of these people wondered if they had found, bought or inherited a meteorite”, and ends with “Other scientists who study meteorites have had the same experience and most no longer answer questions from the public”.

If you give people money, they’ll be happy to say you didn’t find a meteor. Prices vary from lab to lab, but it’s not incredibly expensive: New England Weather Services, for example, will test a small sample of your rock for only $30. (I have no idea how good they are and don’t recommend them, just giving you an idea of ​​the price.)

The other option is to simply tell everyone you found a meteor. Unless you’re friends with geologists, who’s going to know?

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