“It looks like a meteorite”

It is not possible to identify a rock as a meteorite from a photograph.

Many people tell me that their rock “looks like” some meteorite in a photo they saw. There is no polite way to say this – most people do not know what to look for.

The two rocks below look similar to each other. The one on the left is a meteorite, the one on the right is not – it is a big chunk of terrestrial hematite. In hand, I think that most experienced meteorite hunters and collectors would recognize the one on the left as a meteorite because they know what to look for.

The meteorite attracts a ceramic magnet; the meteorwrong does not. The meteorite has a smooth fusion crust. (Look hard and you can see contraction cracks in the glass.) The meteorwrong has a rougher surface texture. You cannot tell by looking, but this particular meteorwrong is considerably denser than the meteorite. If you were to cut pieces off, metal grains would be visible in the interior of the meteorite whereas the interior of the meteorwrong (and the sawdust) would be the same rusty-red color as the exterior. The meteorite is an unnamed ordinary chondrite from the Sahara Desert. Thanks to Richard Hagar for loan of the meteorite.

It is often not possible to determine whether a rock is a meteorite simply from its appearance, particularly in a photograph and especially in the absence of a fusion crust or iron-nickel metal. Achondrites (e.g., meteorites from Moon, Mars, and asteroid 4 Vesta) can look very much like some types of common Earth rocks. They contain the same minerals (mainly pyroxene, olivine, and plagioclase) and were formed by the same processes. Many achondrites are impact breccias, however. Impact breccias are rare on earth, but there are many earth rocks that resemble impact breccias.

Final words: For the reasons reviewed above, apps and tools such as Google Lens or Google Images are nearly always wrong if they suggest that your rock is a meteorite. It might “look like” a meteorite to whatever algorithm these tools use to identify things, but such suggestions are only poor advice. Also, some to many of the rocks offered for sale as meteorites on Etsy, Pinterest, ebay and other sites catering to sellers are not meteorites. Many of the rocks do not even look like meteorites. They are sold by people who want to make money, not by people who know about meteorites. Caveat emptor.