So you think you’ve found a meteorite? How can you be sure?
Many people find unusual rocks or pieces of metal and wonder if they might have found a meteorite. Meteorites have several properties that help distinguish them from other rocks:
- Density: Meteorites are usually quite heavy for their size, since they contain metallic iron and dense minerals. So pop it on the scales and see how much it weighs compared to a simlar-sized piece of rock from your garden.
- Magnetic:
Since most meteorites contain metallic iron, a magnet will often stick to them.Don’t try sticking a magnet to it! Instead, hang the magnet by a string, it will be attracted if the object is magnetic. - Unusual shape: iron-nickel meteorites are rarely rounded. Instead, they have an irregular shape with unusual pits like finger prints in their surface called “regmaglypts.”
- Fusion crust: stony meteorites typically have a thin crust on their surface where it melted as it passed through the atmosphere.
Why do we advise against testing for magnetism using a fridge magnet? Even small fridge magnets can damage the internal magnetic structure of the meteorite and we’d like to preserve this.
Meteorites do not have the following:
- Light-colored crystals: Quartz is a common, light-colored crystal in Earth’s crust, but it is not found on other bodies in the solar system. Some rare meteorites are light in colour, but they still don’t contain quartz.
- Bubbles: volcanic rocks or metallic slag on Earth often have bubbles or vesicles in them, but freshly-fallen meteorites do not.
- Streak: if you scratch a meteorite on an unglazed ceramic surface, it should not leave a streak. A dense rock that leaves a black or red streak probably contains the iron minerals magnetite or hematite, respectively, neither of which are typically found in meteorites.
- Fossils: it might sound really obvious, but meteorites never have fossils in them !
You can find out more about meteorite identification at these links, but please note again we ask you not to try the magnetism test.
https://www.usgs.gov/faqs/i-think-i-found-a-meteorite-how-can-i-tell-sure
What if I Think i DO have a Meteorite?
You should take it to your local geology or science museum for further assessment. Meanwhile, handle it as little as possible please. Wrap it in kitchen foil and put it into a sealable bag, then keep it in the fridge. Make a careful note of exactly where and when you found it, ideally with a geo-tagged photograph using a mobile phone.