Pyroxene Pallasites (PXP)

Pyroxene Pallasites (PXP) Mineralogy: PXPs contain minor clinopyroxenes, which occur as inclusions in the olivine crystals, as large grains in the nickel-iron matrix, and as grains bordering the olivines. They share similar elemental and isotopic compositions distinct from the main group and Eagle Station pallasites, indicating that the PXPs represent a third parent body on which pallasites were formed. Formation history & Origin: Comparisons made to the groups of iron meteorites yielded no match, inferring that the pyroxene pallasites represent a previously unsampled asteroid. Members: This is another small grouplet, consisting of just four members – the pyroxene-rich, Antarctic pallasite, Yamato 8451, Vermillion, an unusual pallasite that was found in Kansas, USA, in 1991, NWA 1911, and a more recent find from Africa named Zinder. Since the discovery of Vermillion, two more pyroxene-bearing pallasites have been discovered, Zinder and the NWA 1911. The pyroxene-bearing pallasite Zinder, a 46 g pyroxene-rich (28 vol%) pallasite, was found in Niger in 1999. The pyroxene-bearing pallasite NWA 1911, a 53 g pyroxene-rich pallasite (~26 vol%), was found in Northwest Africa.