Few minerals in this world
(and beyond!) capture the imagination as do meteorites. One only
need recall the recent spate of movies featuring civilization-destroying
meteor impacts to realize the awe and fear these natural phenomena
inspire in us all. While the rhetoric regarding the chances of
our imminent demise may have subsided, the realization how meteors
have literally impacted upon life on earth cannot be underestimated.
Once dismissed as flights of fancy, most serious earth scientists
now concur that meteorite impacts have repeatedly changed the
course of the development of life over the eons, often causing
the destruction of over 90% of life on earth on more than one
occasion. Furthermore, one respected theory exists that meteorites
may have transported from space the necessary organic molecules
to start life here on earth! Heady stuff, indeed!
When still in outer space,
these objects are referred to as meteoroids. When they are burning
through earths atmosphere they are known as meteors, or
shooting stars. Finally, if any remnants survive
the fall and land on earth, they are categorized as meteorites.
If they are seen descending to earth and are recovered, those
meteorites are called falls. Conversely, if the descent
is never seen they are referred to as finds.
Falls, or finds
can be further broken down into meteorites categorized by composition.
The most common type of meteorite, comprising of fully 86% of
the material which reaches earth, are chondrites, which are mostly
silicate material mixed with organic compounds - the same material
which formed most of our planets. Comprising of 8% of meteorites
are the achondrites, which are primarily igneous rocks which
come mostly from asteroids. The last two types of meteorites,
iron and stony-iron, make up only some 6% of meteorites which
fall to earth, but constitute the most sought after meteorites
for collectors. The beautiful forms and burnished patinas which
these meteorites take on are true natural works of art. When
sliced, the insides reveal nickel-iron crystalline matrixes of
breathtaking patterns suitable for display. Cut into jewelry,
they make incredibly unique items of almost unparalled strength!