.42" Polished Ureilite Meteorite (.42g) Slice - NWA 12321

The NWA 12321 Ureilite Meteorite

NWA 12321 is a rare type of primitive achondrite meteorite known as a Ureilite. It was found in 2004 and has a total known mass of only 194 grams.

Meteoritical Bulletin Entry - NWA 12321

About Ureilite Meteorites

Ureilite meteorites are a rare and scientifically intriguing class of stony meteorites, representing only about 1% of all meteorite finds. They are notable for their high carbon content, which includes graphite, amorphous carbon, and, in some cases, microscopic diamonds. These diamonds are believed to have formed due to high-pressure shock events, likely caused by violent impacts in space, making them a standout feature in the meteorite world.

Unlike many other types of meteorites, ureilites are not chondrites; they are classified as achondrites because they lack the round, grain-like structures known as chondrules. Instead, ureilites are composed mainly of olivine and pyroxene minerals, mixed with metallic iron and nickel. This composition, along with their carbon inclusions, gives ureilites a distinctive appearance—often dark with shiny metal flecks and carbon-rich veins running through them.

Scientists believe that ureilites originated from a differentiated parent body, likely a large asteroid or protoplanet that underwent significant melting and impact processes early in the solar system’s history. This parent body may have been partially disrupted by collisions, spreading fragments across space, some of which eventually fell to Earth as meteorites. Ureilites thus offer valuable insights into the processes of planetary differentiation and the violent collisions that shaped the early solar system.