Gandom Beryan 009        31°52’50.10"N, 57°10’54.06"E

Kerman, Iran

Find: 4 Jan 2017

Classification: Ordinary chondrite (H5)

History: A 217.9 g meteorite was found 4 January 2017 by the UrFU meteorite expedition-2017 in Iran (Pastukhovich A.Yu., Larionov M.Yu., Kruglikov N.A., Zamyatin D.A.), 5.3 km northeast of the middle part of the Ravar road near Dige-e-Rostam hot springs, Tabas (northern sandy part of the Lut desert). This meteorite was observed on the hard surface and was initially broken into two fragments.

Physical characteristics: Both fragments have roughly rounded shape. The surface and interior of the meteorite is light to dark brown in color due to abundant Fe-hydroxides. Some parts have a glassy-like surface due to desert weathering. No fusion crust was observed. Cracks (up to 0.5 mm in thickness) occur in meteorite fragments. Some are totally filled with natrojarosite or aggregate of natrojarosite and anhydrite.

Petrography: Classification (V.V. Sharygin, SIGM and UrFU). Petrographic observation of a polished section shows chondrules in a recrystallized matrix. Chondrules are readily delineated and their sizes vary from 300 to 800 μm. They have barred or porphyritic texture, rarely cryptocrystalline, and consist of Ol+Pl, Opx+Pl, Ol+Opx+Cpx+Pl or Opx+Cpx+Pl. Olivine, low-Ca-pyroxene and plagioclase are the main minerals in the matrix. Plagioclase grains are less than 50 μm. This indicates a petrologic type of 5 for the meteorite. Undulatory extinction and irregular fractures in olivine, as well as the absence of opaque shock veins and melt pockets, indicate a shock stage of S2. Some grains of pyroxene show polysynthetical twinning. Fresh FeNi metals and troilite (up to 10 μm) very rarely occur in recrystallized matrix due to intensive alteration. Individual grains/blebs (5-10 μm) of kamacite (± tetrataenite ± troilite) and troilite are observed only in some cryptocrystalline chondrules. Weathering products (goethite, "hydrogoethite", natrojarosite, rarely anhydrite) occur as veins and in situ alteration of FeNi-metals and troilite. In addition Fe-hydroxides fill all microfractures in minerals from matrix and chondrules. The replacement of olivine and low-Ca pyroxene by Fe-rich serpentine is sometimes fixed in outer zones of grains (weathering grade W3 to W4). Clinopyroxene, chromite, chlorapatite and merrillite (up to 200 μm) occur locally in the matrix. Micron-sized ilmenite was found in some chondrules. Rare magnetite occurs as rim around some chromite grains. Ni-rich pyrrhotite/smythite and pyrite (alteration of troilite?) is sometimes present in goethite aggregate.

Geochemistry: EDS-WDS analyses (V. V. Sharygin, SIGM and UrFU). The primary chondrite paragenesis includes olivine Fa_19.85±0.11 (N=41), orthopyroxene Fs_17.20±0.26Wo_1.14±0.24 (N=47), plagioclase Ab_82.2An_12.2Or_5.6 (N=27), Cr-bearing clinopyroxene En_47.8Fs_6.9Wo_45.3 (N=13), chromite Crt_80.68±0.71Spl_14.41±0.80 (N=9), chlorapatite and merrillite. Chlorapatite contains F (up to 0.6 wt.%); Cl 5.63 wt.% (N=5). Merrillite is poor in FeO (0.9-1.3 wt.%, N=4). Composition of kamacite (in wt.%, N=23): Fe 89.59±0.23, Ni 9.7±0.36, Co 0.42±0.06. Rare troilite is close to ideal FeS. Composition of pyrrhotite/smythite (in wt.%): Fe 55.0-60.1; Ni 0.4-4.5; Co up to 0.3; S 38.4-40.3. Fe-rich serpentine-group mineral is sometimes rich in NiO (up to 2.6 wt.%). Goethite contains 0.7-16.9 wt.% NiO and up to 0.7 wt.% CoO. Natrojarosite NaFe₃(SO4)₂(OH)₆ (in wt.%, N=9): Fe₂O₃ 46.47; Na₂O 5.18; K₂O 0.69; SO₃ 33.86.

Classification: V. V. Sharygin, SIGM and UrFU). Ordinary chondrite. H5, S2, W3-4. In chemical composition of olivine and low-Ca pyroxene this meteorite seems to be similar to nearby meteorites: Gandom Beryan 002, 005, 006, 007 and Ravar 001.

Specimens: 210.92 g (2 samples: 195.8 and 13.12) at UrFU; 7.0 g cut-offs and thin section at SIGM.