Northwest Africa 13268 (NWA 13268)

Algeria

Find: 2013

Classification: Ordinary chondrite (H4/5)

History: The meteorite has been found by nomads in Algeria in 2013. Later a Hungarian IMCA member, Zsolt Kereszty purchased this specimen from a Moroccan dealer. In the end Hungarian scientific journalist and meteorite collector Nandor Rezsabek bought it for his private meteorite collection in 21 June 2017.

Physical characteristics: A single angular dark brown stone (333.2 g) with weathered fusion crust on its two sides. Elongated regmaglypts with faint remnants of flowlines on one of the crusted sides are observable. Where the brownish black fusion crust is absent several shiny metal grains are visible and chondrules bulge out from the matrix. Cut surface reveals porous inner material. Broken surfaces show significant amount of brown alteration products.

Petrography: (D. Rezes, CSFK) The stone has chondritic texture with mostly well-defined chondrules. However, some chondrules show transition to less delineated state. Chondrules are relatively small, although some of them reach 2 mm in diameter. Igneous glass in chondrules is not observable. The texture is porous with pores up to 0.5 mm in diameter. FeNi metal and troilite show heavy oxidation without the alteration of mafic silicates. Olivine shows irregular fractures, the optical extinction is weakly undulatory. Shock veins are absent. Cl-apatite as accessory mineral is identified.

Geochemistry: (D. Rezes and M. Szabo, CSFK) Mineral chemistry: Olivine Fa_16.81±0.45, Fe/Mn=23.6±3.3, N=21; Low-Ca pyroxene Fs_14.90±0.61Wo_1.34±0.20, Fe/Mn=13.6±1.7, N=21; Feldspar Ab_80.51±1.43, N=11

Classification: Ordinary chondrite (H4/5), shock stage S2, weathering W3.

Specimens: 20 g on deposit at CSFK, N. Rezsabek holds the main mass including one polished thin section.