The following characteristics are common to most meteorites.
1. Most meteorites contain some iron and tend to be very heavy. Iron
meteorites are approximately four times as heavy as a terrestrial rock of
the same size; stone meteorites about three times as heavy.
2. Meteorites usually have a smooth surface with rounded corners. They are
never porous like some types of lava (pumice, for example).
3. Fresh meteorites will have a dark gray or black surface. Weathered
meteorites will appear brown or rusty.
4. The surface of most meteorites -- particularly if they have fallen
recently -- will exhibit a "fusion crust," caused by burning in the upper
atmosphere. At least some trace of fusion crust is usually visible on the
5. Sometimes the surface will display tiny "flow lines," showing where
melted material flowed off the surface upon atmospheric entry.
6. Indentations called "thumb prints" are also common. They really do look
like they were made by someone pushing their thumbs into soft clay. Thumb
prints in solid iron meteorites will often consist of deeper, rounded
holes -- plum-sized or larger.
7. The interior colors will differ, but after grinding or polishing, most
will reveal tiny silver-metallic flecks. Solid iron meteorites have a very
bright solid "chrome" interior when cut or ground.
8. Magnets are almost always attracted to meteorites. In fact, if your
sample does not attract a magnet, it's about 99.9% certain that it is not
a meteorite. Iron meteorites are very strongly attracted to powerful
magnets, however a common refrigerator magnet may be too weak to
demonstrate a noticeable pull towards a meteorite. If you are testing a
potential meteorite with a magnet, first ensure that the magnet is not
attached to any other metallic objects, then attach it to a piece of
string. While holding one end of the string, touch the suspended magnet to
the test rock and slowly back away.
Remember that there are also some terrestrial rocks that contain iron, as
well as many manufactured materials that have been mistaken for meteorites
in the past (rusted tools, cannon balls, artillery shell or bomb case
fragments, iron foundry slag, etc.). Sometimes a laboratory test is
necessary to determine the authenticity of a meteorite; sometimes a brief
examination by an expert is all that is needed.
There are many different kinds of meteorites, some with unique
characteristics which may be different from those listed above. These
atypical meteorites are often very fragile and are prone to rapid
deterioration. Unless they are actually seen to fall they are unlikely
ever to be identified or recovered.
Of those atypical specimens that have been recovered, most have been found
in barren deserts or in Antarctica, where the odds are very good that any
found rock will be a meteorite. Hence, the preceding characteristics will
probably apply to 99% of new meteorite finds.
Are meteorites only found in craters?
Meteorites do not always cause craters. Meteors (a meteorite, before it
hits the ground) will sometimes explode and break up into many smaller
pieces while still traveling rapidly through the air. These explosions can
produce hundreds or even thousands of fragments, which may be scattered
over a large area -- typically 25km long and 12km wide. This area is
referred to as a "strewn field." Meteorites in strewn fields are sometimes
found lying right on the surface.
By examining the surface of a meteorite, it is sometimes clear that it was
once part of a larger mass, or that a smaller piece may have broken away
from it. In such a case, an area search covering several square miles
around the initial find may turn up the missing piece(s).
Metallic and Stony Meteorite
Common terrestrial rocks are often mistaken for meteorites
Common terrestrial rocks are often mistaken for meteorites , and we
affectionately call them "meteor-wrongs."
Meteorites never hit the ground burning, no matter what you might see in
science fiction movies. If you see a meteor fireball streaking across the
sky, the odds are that it landed hundreds of miles away, not "just on the
other side of those trees!" However, if you hear a sonic boom, then the
fireball may well have burned out almost directly overhead (nearly 9km
up), and you may be relatively close to the point of impact -- perhaps 35
Some examples that are NOT meteorites...
the sedimentary iron oxide ore hematite - soft, will mark paper with a
large sedimentary concretion in mudstone - note sedimentary bedding
Mining slag (molten waste rock) - note flow lines throughout not
just on surface
Iron concretion usually forms in anerobic swamps
Vesicular basalt lava - gas bubbles expand on exit from volcano