- Subject: METEORITE INFORMATION
Meteorites are rocks from space. Most originate within the Asteroid Belt though a few come from Mars and the Moon. Some may be fragments of comets, though there is no strong evidence to support this view.
Thousands of meteorites fall to Earth each year. Most land in the ocean and in sparsely populated areas to become lost forever. But a few – just a few -land in or near towns and cities where they are rapidly recovered to eventually find their way into both public and private collections.
Prior to 1969 there were a little over 2,000 known meteorites. A chance discovery in Antarctica, however, led to searches for other specimens with the result that more than 10,000 new meteorites have since been found trapped in the blue ice.
Meteorites fall (no pun intended!) into three broad categories. The so-called irons are composed mainly of nickel-iron alloys and, when correctly treated, can reveal a variety of patterns – such as Widmanstatten Lamellae shown in the title illustration of this page. You can usually tell an iron meteorite because of its weight – they are very heavy.
The stones are similar in some ways to terrestrial rocks and are often the hardest to distinguish. This is particularly true of the group known as the achondrites, though a second group – the chondrites – often contain small beads, or chondrules the like of which is unknown in Earthly rocks.
Finally, the stony-irons are, not surprisingly, a mixture of stone and iron. One stony-iron group in particular – the pallasites – are among the most attractive meteorites to be found, consisting of rich greenish olivine crystals set in an iron matrix.
In recent years meteorite collecting has become quite popular. You can learn more about this subject by reading The Meteorite and Tektite Collector’s Handbook