• Type: Achondrite / Diogenite
• Location: Western Sahara
• Weight: 0.1g
• Dimensions: 5 x 4 x 4 mm
• Year of discovery: 2013
• Known total weight: 20 kg
• Surface treatment: none – Rough
• Packaging: transparent plastic box (5.8 x 3.8 x 1.6 cm)
• DETAILED DESCRIPTION

The NWA 7831 meteorite – a diogenite from inside Vesta The NWA 7831 meteorite is a fascinating example of a diogenite, a type of achondrite that originated from the mantle of the asteroid Vesta. It was discovered in March 2013 in Saguia el Hamra, Western Sahara. The total mass of all recovered fragments is approximately 20 kilograms. Diogenites, including NWA 7831, are deep igneous rocks that formed beneath the surface of Vesta, one of the largest objects in the main asteroid belt between Mars and Jupiter. Vesta is considered a protoplanet with a differentiated planetary structure, meaning it has a core, mantle, and crust, similar to terrestrial planets. Diogenites contain high amounts of pyroxene, a mineral rich in iron and magnesium, and often include minor amounts of olivine and plagioclase. NWA 7831 is particularly known for its composition, which includes distinct yellowish-green orthopyroxene crystals. This mineral is relatively rare in meteorites and its presence suggests specific crystallization conditions that occurred deep within Vesta's mantle. Dawn Mission and the origin of diogenites The Dawn spacecraft, which studied the asteroid Vesta between 2011 and 2012, provided fundamental data used to compare terrestrial finds like NWA 7831 with Vesta's surface and subsurface structures. This allowed scientists to confirm that certain types of meteorites, including diogenites, originated precisely from this asteroid. Research results have shown that diogenites were ejected from Vesta during impacts with other asteroids and subsequently reached Earth as meteorites.