D'Orbigny

Country: Argentina
Recognized: 1998
Group: Stone
Type: Achondrite
Class: Angrite
Total known weight: 16.8 kg

A 16.55kg stone, mostly covered with dark gray fusion crust, was found in a corn field after a farmer hit it with a plow; classification and mineralogy: has a subophitic texture, exhibiting laths of plagioclase with subhedral to euhedral augite and anhedral to subhedral olivine; augite shows marked optical zoning, with cores and reddish-brown rims; olivine is zoned. Anhedral kirschsteinite is intergrown with olivine; in places, abundant ultrabasic glass fills pore spaces; minor to accessory phases include transparent brownish spinel (up to 500 µm), ulvöspinel, troilite, and a silicophosphate; contains abundant round vugs, up to 2.3cm in diameter, and druses containing augite and rare cm-sized green olivine crystals; rock is fresh, but pores contain variable amounts of caliche (J.N.Grossman and J.Zipfel)