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Stony
meteorites are the most common type of meteorite falling to earth,
comprising more than 90% of observed falls.
FRESH
FALLS. The
stony meteorite shown below (a half-pound specimen approximately 2.5
inches across) fell in Iowa in 1875.

This stone was recovered immediately after falling, and nicely illustrates the properties of a freshly-fallen
meteorite:
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The stone's
surface is covered by a thin black fusion crust that formed during the
stone's passage through Earth's atmosphere.
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The stone's
surface is smooth and exhibits shallow "thumb-prints"
that formed by aerodynamic sculpting. Meteorites are never porous like
volcanic rocks.
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The stone has a
light-colored interior (visible through fractures in the fusion crust).
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The stone is
heavy for its size (heavier than ordinary rocks).
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The stone is
attracted toward a good magnet due the presence of small metal particles.
WEATHERED
FINDS. Most meteorites fell to Earth long ago,
without being witnessed by humans. Such meteorites, known as meteorite finds, are rusty-brown like an old tin.

The weathered stone on the left (1 pound
and about 2.5 inches long) was found on a cotton farm in western Texas. Rocks
are very uncommon in the area, and this stone piqued the curiosity of the
farmer. The author purchased this and several other stones from the
landowner in 1990. Note the smooth, rusted appearance.
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METAL
PARTICLES.
This photo shows the interior of a weathered stony meteorite. Many small,
silver-colored Fe-Ni metal flakes are sprinkled throughout the dark (rust-stained)
stony matrix. Fe-Ni metal particles occur only in meteorites and are
conclusive evidence of a cosmic origin.
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CHONDRULES.
When cut open, many stony meteorites exhibit small spheres known as "chondrules".
This photo shows the interior of a stony meteorite that landed in Ireland in 1969.
The slice exhibits
numerous, well-defined chondrules. In most stony meteorites, chondrules are
less abundant and less well-defined. A few traces of chondrules can be
seen in the weathered chondrite pictured above.
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