Nagara        35°26’33.9"N, 136°46’51.5"E

Chubu, Japan

Find: 2012 Oct

Classification: Iron meteorite (IAB-MG)

History: A 6.5 kg piece of iron was discovered by Mr. K. Mitsumura in October, 2012, among stones plowed from his chestnut yard in Nagara, Gifu city, Gifu prefecture, Japan. Mr. Mitsumura took the specimen to his home and kept it till June, 2017. Eventually, he considered that it might be a meteorite and the specimen was brought by his friend Mr. H. Iwasa to S. Kawakami at Gifu Shotoku Gakuen Univ. Then, the specimen was sent to T. Mikouchi, UTok for identification. A second 9.7 kg mass was found later.

Physical characteristics: The 6.5 kg mass has an exterior with several rounded ridges and shows a brownish dark surface color coated by rust.

Petrography: Polished sections (all ca. 12 × 6 mm in sizes) show no Widmanstatten pattern and >95% of the sections consist of kamacite with veins of terrestrial weathering products (up to 0.5 mm wide). Rare schreibersite is present at the interior of such weathered veins. Taenite is present as small elongated grains (~0.1 mm wide and ~0.5 mm long) with less than 0.1% abundance.

Geochemistry: Electron microprobe analysis (T. Mikouchi, UTok): Fe=92.0-94.5, Ni=5.5-6.5 and Co=0.55-0.65 for kamacite (N=549), Fe=45-54, Ni=30-38 and P=15 for schreibersite (N=26), and Fe=61-65, Ni=34-39 and Co=0.1-0.2 for taenite (N=9). LA-ICP-MS data (A. Yamaguchi, NIPR and N. Shirai at Tokyo Met. U.): Ni=6.10, (in wt%); Ir=4.25, Ga=91.6, Ge=402, Au=1.58 (all μg/g, average of ~5 mm long 4 traverses on the section).

Classification: IAB-MG

Specimens: UTok: 52.7 g slice (after cutting of small chips for polished mounts) and NIPR: 3 polished mounts