Meteorite Testing

by Kevin Kilkenny

While I'm no expert, I believe I can lead you to finding out if your meteorite is genuine. But before I begin, I would like to let you know that it is against the law to go prospecting on land that isn't your own without permission. Look what happened to the discoverers of Sue the T-Rex! Get the landowners permission (especially on gov't. property) before going on your hunt.

If you have already found what you think is a meteorite, there are four (4) simple tests you can make right away to help determine this:

1. The first thing to do is look the specimen over. There may be parts of the rock (if not the whole outer covering) that may be almost shiny black. This is the fusion crust and results from passage through the Earth's atmosphere. Others that have been subjected to Earth's weather for any length of time will appear rusted or deeply weathered. Many meteorites are found because they "just look different" from the surrounding terrestrial stones.

2. Your specimen may also contain what is known as regmaglypts. These are little indentations in the specimen as if someone had pressed their thumb into clay all over the piece. This is a result of uneven melting during the passage through the atmosphere.

See our photos for some examples of meteorites

3. A third test to make is simply to lift the specimen to see how much it weighs. Meteorites are usually much heavier than an Earth rock of the same size.

4. A final test it to see if the specimen is magnetic. Even stony meteorites have enough metal in them to attract a magnet. By a magnet I don't mean a kitchen souvenir refrigerator magnet - you'll need a real magnet. Put it on a string and place it near the specimen. The rock should attract the magnet in some form whether a gentle sway of the string or outright attraction.

These are the first four steps to take in identifying a possible meteorite. But since earthly rocks can also rust or can attract a magnet, to absolutely prove that you have a genuine meteorite it is necessary to have it tested in a lab. Other identification tips and a list of labs can be found at http://www.meteoritearticles.com/foundmeteorite.html. The Meteoritics Laboratory at Northern Arizona University in Flagstaff, Arizona has an excellent site discussing meteorite testing. For general information see http://www4.nau.edu/meteorite/ or for specific identification help visit http://www4.nau.edu/meteorite/Meteorite/Book-Identification.html

How much do I send? The Nomenclature Committee of the Meteoritical Society has established a minimum quantity for authentication and naming of a meteorite: that is, 20% or 20 g, (28 grams = 1 ounce) whichever is less. For classification services, a lab may require more.

Due to the number of viruses and worms that are making the rounds throughout the web, I no longer feel safe accepting images, either imbedded in e-mails or as attachments. But there are ways around this problem. There are also a number of sites that let you show your photos on the web. Try - http://photos.yahoo.com which is free, as well as www.ofoto.com and www.dotphoto.com. Once your photo is online, direct me to the site and I will have a look. I apologize for this but as of now it can't be helped.

Please make sure the photos are sharp and have an uncluttered background if possible. Also try to have at least one close-up. Most cameras have a "macro" setting for just such a purpose.

You may also have a better chance of finding a meteorite if you look (or have looked) in a known strewn field (remember my permission statement). Meteorites are usually named after the closest post office to their discovery. A secondary means is the county of the discovery. I know you may want to keep your "discovery" secret, but by telling me the nearest post office name and/or county and state I can try to look to see if you've been in a known strewn field on a master listing. Also, I live in New York City, so I'm not about to travel the country to "claim jump" your meteorites. ;-)

If you have any other questions, email me at the address below. Good luck!

Kevin Kilkenny
fireball@namnmeteors.org