Diogenite - HED Achondrite

Diogenites are a group of Achondrite meteorites belonging to the HED family, alongside Howardites and Eucrites. They are strongly linked to asteroid 4 Vesta, a differentiated body in the asteroid belt that was studied in detail by NASA’s Dawn mission. Unlike Chondrites, Diogenites do not contain chondrules and instead formed through igneous processes inside their parent body. They are thought to represent material from deeper within Vesta’s crust or upper mantle, excavated by later impacts and eventually delivered to Earth as meteorites.

Diogenites are typically coarse-grained and dominated by orthopyroxene, often giving them a pale grey, greenish, or yellow-green crystalline appearance. Their larger crystal size reflects slower cooling beneath the surface, distinguishing them from finer-grained Eucrites, which represent basaltic crustal material. Some Diogenites are brecciated, showing evidence of impact fragmentation and mixing, while others preserve a more uniform crystalline structure.

Studying Diogenites provides valuable insight into the deeper layers of Vesta and the processes of melting, cooling, and differentiation on early planetary bodies. They help scientists understand how small worlds developed internal structure and how impacts exposed deeper material over time. For collectors, Diogenites are highly desirable due to their Vestan origin, distinctive mineralogy, and relative rarity. Each specimen represents ancient asteroid material formed deep within one of the solar system’s earliest differentiated bodies.