Fell June 27, 1931
Specimen as found : 7.85g
A piece of the large asteroide Vesta (530Km diameter), under study by DAWN spacecraft (NASA)
Mineralogically, the diogenites are composed primarily of magnesium-rich orthopyroxene, with only minor amounts of olivine and plagioclase. The pyroxenes are usually coarse-grained, suggesting a cumulate origin for the diogenites in magma chambers within the deeper regions of Vesta's crust. They are intrusive igneous rocks similar to plutonic rocks found on Earth, and they experienced much lower cooling rates than did the eucrites, which allowed the pyroxene to form sizeable crystals.