NWA 7831 is a Diogenite, part of the HED Achondrite family strongly linked to asteroid 4 Vesta. It was found in 2013 near Chouichiyat in Saguia el Hamra, Western Sahara, as a single large mass of at least 20 kg, much of which fragmented during excavation. As a Diogenite, it represents material from deeper within Vesta’s crust or upper mantle, where minerals crystallised slowly before later impacts excavated and ejected the material into space.

NWA 7831 specimens are known for their yellow-green crystalline material, often with pale orange weathering products along fractures. Prepared pieces can show a coarse, crystalline texture typical of Diogenites, dominated by orthopyroxene-rich material. Some fragments may retain weathered exterior surfaces, while cut faces reveal the mineral structure more clearly. Its colour and texture give it a distinctive appearance compared with many darker HED meteorites.

Studying NWA 7831 provides valuable insight into the deeper layers of asteroid 4 Vesta, as well as the cooling and crystallisation processes that shaped its interior. For collectors, it offers a visually interesting and well-documented Diogenite with a clear Vestan connection. Each specimen represents ancient, slowly cooled asteroid material, later shaped by impact events and delivered to Earth.