Slag- Also called cinder or runoff. One of the most commonly found meteor-wrongs. Often mistaken for a meteorite because of its melted look and is found everywhere. Magnetite and Hematite- Often mistaken for meteorites because they are magnetic. The first picture is magnetite, while the second group of pictures features different kinds of hematite. Dark black rocks- ex. Magnetism: A majority of meteorites are magnetic. Streak Test: Scratch your specimen on a ceramic tile.
If it is a red or brown streak, you probably have hematite. Nickel Test: Run a chemical test for nickel. If the proportion of nickel is inside the range for meteorites, you may have a meteorite. Fusion Crust Test: Fusion crust is a thin, dark rind formed on a meteorite as it streaks through our atmosphere. It does not occur on earth rocks and will disappear over time due to weathering, but it can be seen on some fresh meteorites.
The absence of a fusion crust does not mean a specimen is not a meteorite. Regmaglypts Test: Regmaglypts, also known as thumbprints, are unique to meteorites. If there is an easily visible crystal structure it might not be a meteorite. This is not conclusive because some of the rarer meteorites do have some crystal structure.
However, most ordinary meteorites do not unless viewed under a microscope. Most meteorites are cold when they hit the Earth's surface and do not start fires on the ground. Their trip through the atmosphere is short and the friction heat that burns up the outside does not have a chance to heat up the inside of the meteorite.
Meteorites are made of the same elements and minerals as terrestrial rocks and are not any more radioactive than terrestrial rocks, so you can't find them with a Geiger counter. Streak is what the rock leaves behind, like a crayon. Common ceramic tile, such as a bathroom or kitchen tile, has a smooth glazed slide and an unfinished dull side which is stuck to the wall when installed. Take the sample that you think is a meteorite and scratch it vigorously on the unglazed side of the tile.
If it leaves a black gray streak the sample is almost certainly magnetite, and if it leaves a red-brown streak it is almost certainly hematite. A meteorite, unless it is very heavily weathered, will not leave a streak on the tile. If you don't have a ceramic tile, you can also use the inside of your toilet tank cover the heavy rectangular lid on top of the tank - it is heavy, so be careful.
Human activity has produced objects made from pure iron for centuries, so it is possible to confuse lumps of man-made iron with meteoritic materials. Objects such as iron grinding balls often have a smooth rounded appearance and may be thought be meteorites. Lumps of iron slag from smelting processes can also have some similarities to meteorites, so it is important to be careful. The major difference between iron produced by human activity and meteoritic iron is the presence of the element nickel.
Iron metal in all meteorites contains at least some nickel whereas man-made metal objects generally do not. In addition, the interior structure of iron meteorites is unique and unlike any man-made metal alloys. Special analysis and preparation techniques are required to examine the internal structure and composition of a suspect meteorite. The results of such tests are, however, completely definitive. For information on hunting for meteorites in New Mexico, please visit this page.
Pages originally compiled by David Draper using Open-source web design template by G. William B. Banner image by Bill Tondreau , used with permission. Fusion crust Meteorites which have fallen recently may have a black "ash-like" crust on their surface. Regmaglypts The surface of a meteorite is generally very smooth and featureless, but often has shallow depressions and deep cavities resembling clearly visible thumbprints in wet clay or Play-Doh.
Almost all meteorites contain extraterrestrial nickel and iron, and those that contain no iron at all are so rare that when we are asked for help and advice on identifying possible space rocks, we usually discount anything that does not contain significant amounts of metal. Much of meteorite classification is based, in fact, on how much iron a specimen does contain. Stone Meteorite: A It was a witnessed fall and is a rare type of achondrite—a stone meteorite which does not contain chondrules.
Eucrites are volcanic rocks from other bodies in the solar system, and Millbillillie is one of the very few meteorites which does not contain iron-nickel. Note the glossy black fusion crust, and fine flow lines which were caused as the surface of the meteorite melted during flight. This specimen is also highly oriented, with a textbook snub-nosed leading edge pictured and a flat back.
When I give lectures and slideshows about meteorites to rock and mineral societies, museums, and schools, I always enjoy commencing the presentation by passing around a softball-sized iron meteorite.
Most people have never held a space rock in their hands and when someone does pick up an iron meteorite for the first time their face lights up and their reaction is, almost without fail, to exclaim: "Wow, it's so heavy! Iron meteorites were once part of the core of a long-vanished planet or large asteroid and are believed to have originated within the Asteroid Belt between Mars and Jupiter.
They are among the densest materials on earth and will stick very strongly to a powerful magnet. Iron meteorites are far heavier than most earth rocks-if you've ever lifted up a cannon ball or a slab of iron or steel, you'll get the idea.
Iron meteorites are subdivided into classes both by chemical composition and structure. Structural classes are determined by studying their two component iron-nickel alloys: kamacite and taenite. This remarkable lattice-like arrangement can be very beautiful and is normally only visible when iron meteorites are cut into slabs, polished, and then etched with a mild solution of nitric acid. The kamacite crystals revealed by this process are measured and the average bandwidth is used to subdivide iron meteorites into a number of structural classes.
An iron with very narrow bands, less than 1 mm, would be a "fine octahedrite" and those with wide bands would be called "coarse octahedrites. Stone meteorite: Detail of prepared slice of the carbonaceous chondrite Allende, which was seen to fall in Chihuahua, Mexico on the night of February 8, , following a massive fireball. Allende contains carbonaceous compounds as well as calcium-rich inclusions large white circle near center.
NASA scientist Dr. Elbert King traveled to the site immediately following the fall, and recovered numerous specimens which were traded with institutions around the world, making Allende one of the most widely studied meteorites. The Allende meteorite also contains micro diamonds, and is believed to pre-date the formation of our own solar system. Washington University in St. Nearly all of the photos on this page and in the links below were either sent to me or are ones that I made of rocks that people have sent to me.
I am sent photos of dozens of meteorwrongs every day. Think of it this way: If you see it driving down the freeway and it has 4 wheels, 2 headlights, and a trunk, it is probably an automobile, not an alien spacecraft. The chance of finding a meteorite is exceedingly small. See numbers for the U. Even experienced meteorite hunters can go for years between finds.
The chance of finding a meteorite that has just fallen is even smaller. Only 98 of those occurred in the US. Even when a meteorite is observed to fall, experienced meteorite hunters may find only a few stones when hunting dawn to dusk for a week.
The chance of finding a lunar or martian meteorite is even smaller. Only about 1 in meteorites is from the Moon or Mars. It requires sophisticated chemical or mineralogical tests to distinguish a rock as an achondrite and to identify just what type of achondrite the rock is.
If you found a rock, it might be a meteorite , but it is definitely not a meteor. If you saw a meteor and then found a stone, then the stone is not a meteorite. Not everything that falls from the sky is a meteorite. Achondrites such as meteorites from asteroids, Moon, and Mars can look very much like some types of common Earth rocks.
Some meteorites do not look like meteorites. I have bought several meteorite specimens from such dealers. However, there are foolish or devious people who try to sell backyard rocks as meteorites.
Sometimes you can buy a cheap meteorwrong, however, but it is even cheaper to go find your own. In English, there is only one way to spell meteorite. But be aware — all meteorite experts I know are so deluged with questions by wannabe meteorite finders that most will likely not reply. I get contacted about 20 times a day. So, I do not have time to chat with you and I have no interest in arguing with you if you do not agree with my free opinions.
I am retired. If you do not like my response, contact someone else. Search The Meteoritical Society database. Achondrites look like terrestrial rocks. It is often not possible to determine whether a rock is a meteorite just from its appearance, particularly in a photograph.
Kalahari There are numerous processes on Earth, such as chemical weathering, that cause rocks to have rinds, coatings, and crusts. Fusion crusts are thin because as soon as the exterior of the meteorite melts, the liquid is sloughed off due to of the high velocity of travel of the meteoroid through the atmosphere. Some dark, fine-grained-crystalline earth rocks can be rounded and polished by abrasion to the point where the surfaces become shiny like a meteorite fusion crust.
There are many terrestrial processes that lead to regmaglypt-like depressions in rocks. If the rock does not rather strongly attract a cheap ceramic magnet, then it is probably not a meteorite.
Do not use a rare-earth neodymium magnet to test for magnetic attraction. Meteorites attract magnets because they contain iron-nickel metal. Some sulfide and oxide minerals look like metal. Some of the rarest types of meteorites, the achondrites, do not attract magnets for the same reason that most Earth rocks do not attract magnets — they do not contain magnetite of iron-nickel metal.
Humans have been making and losing metal things for thousands of years. Metal detectors are not that smart. The commonest kind of meteorite, the ordinary chondrites , contain iron-nickel metal. Some rare meteorites, the achondrites, which do not contain metal, have low densities like common Earth rocks. Iron-oxide nodules or concretions are the most common kind of meteorwrong sent to us. Most stony meteorites are smaller than people think they are.
Because meteorites do not contain quartz the hardest common terrestrial mineral , they are not very hard.
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