Shergottite is among the rarest of meteorites. Shergottite consists mostly of olivine
, the pyroxene mineral pigeonite, and plagioclase feldspar
, making it a basalt. Such a rock can only form in a differentiated body, that is, a fairly sizable planet. From studies of its age (much younger than other meteorites) and its gas inclusions (which precisely match the composition of the martian atmosphere), we know that the planet in question is Mars. Here's more about this stone
, officially named Sayh al Uhaymir 094.
Shergottites get their name from the Indian village of Shergotty (Shergahti) in Bihar state, where a dark boulder fell from space on the morning of August 25, 1865.
I also have a picture of another Mars rock, a nakhlite. And find more Mars links in the Mars Geology list.
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