Diogenites belong to the evolved achondrite HED group that also includes howardites and eucrites. They are named after the Greek philosopher Diogenes of Apollonia, of the 5th century BCE, who was the first to suggest that meteorites come from outer space (a realization forgotten for over 2,000 years). They are Click on Term to Read More, anomalous
A rock composed primarily of orthopyroxene. Non-terrestrial orthopyoxenites include diogenites and a single martian meteorite, ALH 84001, that was found in the Allan Hills region of Antarctica in 1984. ALH 84001 is a cumulate rock consisting of 97% coarse-grained, Mg-rich orthopyroxene, with small amounts of plagioclase, chromite, and carbonate. It Click on Term to Read More
(≥90 vol% Orthorhombic, low-Ca pyroxene common in chondrites. Its compositional range runs from all Mg-rich enstatite, MgSiO3 to Fe-rich ferrosilite, FeSiO3. These end-members form an almost complete solid solution where Mg2+ substitutes for Fe2+ up to about 90 mol. % and Ca substitutes no more than ~5 mol. % (higher Ca2+ contents occur Click on Term to Read More)
Found October 2000
18° 43.525′ N., 54° 43.829′ E.
Diagram credit: Greenwood et al., Chemie der Erde, vol. 77, p. 25 (2017)
‘Melting and A process by which a generally homogeneous chondritic body containing mostly metal, silicates and sulfides will melt and form distinct (differentiated) layers of different densities. When the melting process continues for a long enough period of time, the once chondritic body will re-partition into layers of different composition including Click on Term to Read More of early-formed asteroids: The perspective from high precision oxygen isotope studies’
(open access: http://dx.doi.org/10.1016/j.chemer.2016.09.005) The photo above shows a 0.88 g half slice of Dhofar 778, which exhibits profound shock-veining. Increased magnification reveals that fragmentation is present to a very fine scale. It is thought that the melt veins were formed and quenched within a few microseconds. The top photo below is a high resolution image of this Diogenites belong to the evolved achondrite HED group that also includes howardites and eucrites. They are named after the Greek philosopher Diogenes of Apollonia, of the 5th century BCE, who was the first to suggest that meteorites come from outer space (a realization forgotten for over 2,000 years). They are Click on Term to Read More, courtesy of Stephan Kambach. This is a highly polished section revealing a greenish color similar to that of Tatahouine. The bottom photo below shows the fusion-crusted side of the Largest fragment of a meteorite, typically at the time of recovery. Meteorites are commonly cut, sliced or sometimes broken thus reducing the size of the main mass and the resulting largest specimen is called the "largest known mass". Click on Term to Read More.
click on image for a magnified view Photo courtesy of Stephan Kambach
Photos of the complete stone shown courtesy of Stephan Kambach