In the cold, dark, stillness of deep space, 5 billion-year-old pieces of planets travel through our galaxy and solar system. A relative few skip through our atmosphere in a fiery display, pock-mark our Earth, and some of which are eventually discovered, collected and admired by collectors. This fascinating adventure in unrecorded history is what initially attracts the meteorite collector — to hold in one's hand something older than the Earth we live and die upon.

Meteorites aren't the only heavenly bodies which have become earthbound and left their mark. Comets are considered responsible for the ending of the Paleozoic Era 250 million years ago, as well as the ending of the Age of Dinosaurs 65 million years ago. As these travelers are made up of mostly ice and sand, little is left behind to study, aside from their devastating results.

There are three main types of meteorites, with a make up nearly identical to our Earth: the surface stone, called stony meteorites; the mantle, called stony iron; and the iron/nickel core, called iron meteorites. Characteristics of true meteorites are the thin, dark coating from burning through the atmosphere, called the fusion crust; and the circular pitting or indentations on the surfaces, called regmaglypts.

Each meteorite fall is given a name, usually based on the county or nearest city in which it landed or was discovered. There are numerous falls, and serious collectors attempt to collect as many as economically possible. Each meteorite is somewhat different from another: the internal structure might contain a higher or lower nickel content, or perhaps more or less of certain chemicals or materials. Some meteorites are quite small in size, so the finder will often cut it into thin slices to provide opportunities for others to own a piece of it.

Prices for meteorites are dependent on their rarity, size, composition, and eye appeal. A small example of a common iron meteorite may be had for a few dollars, to acquiring a rare piece of a lunar or martian meteorite for several thousand dollars.

 Widmanstatten Lines
Widmanstatten lines are the crosshatching pattern found when the inner surface of a some nickel/iron meteorite is polished and then etched with a weak acid wash. This is unique to meteorites and appears as a result of nickel and iron based minerals Kamacite and Taenite cooling at a supposed rate of approximately one degree every million years, creating a crystalline structure.

 Regmaglypts
Depressions that resemble thumbprints on the outer surface of some meteorites are called regmalypts. These are caused when the meteor streaks through the Earth's atmosphere, causing friction and subsequent melting or ablating of pockets of material.

 Gibeon Nickel/Iron Meteorite
The Gibeon meteorites are plentiful, having come from a large mass which exploded upon entry into the Earth's atmosphere during prehistoric times. The resulting shower fell over a 70 x 230 mile area in southern Namibia situated on the west coast of Africa.

 Sikhote Alin Nickel/Iron Meteorite
Sikhote Alin was a witnessed fall which took place over Eastern Russia on February 12, 1947. Like the Gibeon mass, this very large meteor estimated at 1,000 tons violently exploded approximately 3.5 miles above the Earth. This resulted in two forms of meteorites; shrapnel type, which shows a torn, wrenched appearance to the metal, and those with standard regmaglypts.

 Pallasite Meteorite
Pallasite meteorites are composed of both nickel/iron and rock and are the scarcest of the three meteorite types. Its composition indicates it is likely from the mantle of a planet (as opposed to its crust or core). The crystalline structure is olivine, better known as peridot. The example shown is from the Esquel meteorite, considered the most beautiful example of this type.

 Allende Stony Meteorite
So named for its 1969 fall location in northern Mexico, the Allende meteorite is of the more common stony type, although its particular composition is virtually unique. The interior of this specimen is composed of a variety of chemicals that indicate it is much older than our solar system and perhaps came directly from the "Big Bang".

 Mars Meteorite
Meteorites from the planet Mars are the result of a large meteorite of asteroid striking the surface of Mars at such an angle as to jettison fragments of the planet's surface into space. Examples have been verified as coming from Mars through mineral comparison with rocks inspected by the Mars Rover. To date, only 33 Mars meteorites have been discovered.

Recommended Reading:
Rocks from Space
O. Richard Norton - 1998



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