Meteor Right or Meteor Wrong

Meteorite Identification

How do you know that a rock that you have found is a meteorite or not?

Meteorites have some characteristics that allow us a short list of easy tests to get started on their identification. See if you rock has any of these features and if it does you may be on your way to having discovered a new rock from space.

Meteorites are heavier often then regular Earth rocks. They contain iron metal that is what makes them heavier.

The iron metal also makes them respond to a magnet. So will a magnet stick to the suspect rock is the next test.

Is the rock black or dark brown in color? Meteorites are usually black or dark brown. They become more brown as time passes and they decompose on Earth.

Does the rock in question have an outside coating that looks melted with thumbprints or pits? Meteorite melt on the outside coming through the atmosphere from space. This outer coating is called the fusion crust and it is very durable, lasting for a long time after the meteorite lands.

If the rock is not solid iron as some meteorites are. Are there metal grains inside the rock? This is only slightly harder to determine. With a grinding stone or diamond file a little of the rock must be removed. If the ground off spot shows bright shiny chrome like sparkles of metal then that may be iron grains which many meteorites have.

The color of the ground off material in the previous test can be a signal to the rocks nature as well. The powder of a meteorite will usually be brown. But two often mistaken for meteorite earth rocks give a different color powder. Magnetite which is magnetic and heavy will give a black streak or powder. Hematite also an iron mineral will give a red streak or powder. Brown  is a good color to see for meteorites.

Meteorite Comparison CloseupWhen examining the ground off spot it is also a great opportunity to see if there are chondrules in the stone. Chondrules are round structures quite small but characteristics found in many stone meteorites. Round structures are quite rare in Earth rocks so they are a good indication for meteorite potential.

If a rock passes some or most of these tests it should be looked at by an expert. Laboratories for testing meteorites will want a small sample sent to them. There is usually no cost involved in the testing.