to Do If You Think That Youíve
Iím sorry, but you have not found a meteorite. Yes, your rock is funny-looking and different from other rocks in the area where you found it, but it doesnít have a fusion crust or regmaglypts, so why do you think itís a meteorite at all? Your rock has a rough exterior, unlike the smooth appearance of most stony meteorites. Itís got vesicles (holes), which donít occur in meteorites. Your rock is loaded with quartz or calcite, minerals that donít occur in rocks from other bodies in the Solar System. The density isnít right for a meteorite. On the basis of my experience with the various meteorwrongs that Iíve examined, you probably have a hematite concretion or some kind of industrial by-product (slag). I have heard many wonderful stories from people who swear that they saw the rock fall, that the rock wasnít in their driveway yesterday, or that it split their tree in two. I canít explain how your rock got to be where you found it, but I can say that it is not a meteorite. [Every rock that someone has described as ďit wasnít there yesterdayĒ was just the right size for throwing. Really.] Not everything that falls from the sky is a meteorite.
Even if it is a meteorite, itís not from the Moon or Mars. As I note on my Lunar Meteorites web page, meteorites are rare, lunar meteorites are very rare. Less that 1800 meteorites have been found in the United States in the past 200 years. Less than 1 in 1000 of all known meteorites are from the Moon, and the number is about the same for Mars. No lunar meteorite has yet to be found in the temperate environment of North America or Europe; all were found in deserts of drier continents. Youíve got a better chance of winning big in the lottery than finding a lunar meteorite. You say that your rock attracts a magnet or a compass. Thatís nice. Most (>95%) of meteorites (irons and ordinary chondrites) attract cheap magnets because they contain iron-nickel metal. However, lunar and martian meteorites contain little or no metal, so theyíre not magnetic. (Also, some terrestrial rocks contain magnetite, which is magnetic.) Donít tell me that your rock ďlooks likeĒ one of the photos of a lunar meteorite on my web site. Many kinds of terrestrial rocks ďlook likeĒ lunar meteorites. Finally, I donít want to hear, ďMaybe this is a kind of meteorite nobodyís ever seen before.Ē Get real.
Think of it this
way. If itís driving down the highway and it has 4 tires, 2 headlights, and
a trunk, then itís probably an automobile, not an alien spacecraft.
Look at this information about meteorite statistics. Go through the Self-Test Check-List. If youíre still confused, try my Some Meteorite Realities website where many of the same points are stated in a different way. Look at the photos.
I urge you to saw your rock in two or cut an "end" off with a tile saw. (Or, bring it to a local rock shop where they are likely to have a rock saw. ) Most stony meteorites are ordinary chondrites. Metal grains are easily visible on the sawn face of an ordinary chondrite.
If you contact me, please use e-mail. Do not call me on the telephone and donít send a letter. I do not answer or respond to telephone calls about meteorites. Why? I canít identify meteorites over the telephone. (Nobody can.) Also, I donít hear well and often donít understand people who call me on the phone. If you send a letter, I probably wonít answer it because it takes too much time.† So, e-mail me. Please include a few good digital photos with your e-mail. If the photos are not in focus, they are of no use to me. Include some object like a hand, coin, or ruler in the photographs for scale.
New policy: I am no longer responding to the following types of e-mail.
∑ Your e-mail has little or nothing to do with meteorite identification
∑ I donít know the answer to your question
∑ You didnít ask me a question
∑ No photos are attached
∑ The object in photo is clearly not a meteorite to anyone who has studied the info provided above
∑ There are photos of more than 3 rocks (You think you found more than 3 meteorites!)
∑ The real name of the sender is not evident
∑ Youíve contacted me several times before and Iíve told you your rocks donít look like meteorites
If I think your rock might be a meteorite, I will respond.
If you are particularly certain that your rock is a meteorite and you really want to convince me (or any other scientist), then I urge you to obtain a chemical analysis at a commercial rock-testing laboratory. I recommend Actlabs. Ask for analysis code 4Litho-Meteorite. Please contact me first before sending a sample to Actlabs. I have no financial interest in Actlabs, I just know they do a good job.
Read what they have to say
submittal and sample
preparation. The cost including sample preparation is US$262.50/sample.
Actlabs requests a 5-gram sample (a US nickel weighs 5 grams). However,
they can do the analysis on as little as 1 gram if you request ďno LOIĒ
(loss on ignition, i.e., % weight loss when the sample is heated to a high
temperature). LOI is sometimes useful, but never critical, for determining
whether or not a rock is a meteorite.
Check your own data with "Chemical Composition of Meteorites"
If you have found a chunk of metal that you think might be an iron meteorite, you need to have it analyzed (at a minimum) for iron (Fe), nickel (Ni), chromium (Cr), and manganese (Mn).† Unfortunately, I do not know a lab that does this cheaply.† If somebody out there does, let me know.
October 5, 2015:† I have received results of analyses of
370 samples from Actlabs and more than 100 samples from other labs.† Only two of the rocks were meteorites,
both ordinary chondrites.† The first
was found by a soldier in the Sahara desert, the other was also from the
Sahara and bought by someone who wanted to know if it was ďreal.Ē† (I didnít know the circumstances until
after heíd sent me the results. I was hoping that heíd found it.) So, once
again, finding a real meteorite is highly improbable. †
If you follow my advice about Actlabs, Iíll make a serious study of the analytical report and tell you what I think.
It is impossible to conclusively identify a meteorite from a photograph. Many Earth rocks look like some meteorites. Some meteorites look a lot like Earth rocks.
The rock on the left is the
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