@article{oai:nipr.repo.nii.ac.jp:00004665, author = {Yanai, Keizo and Kojima, Hideyasu}, journal = {Proceedings of the NIPR Symposium on Antarctic Meteorites}, month = {Mar}, note = {P(論文), Yamato-8451 is an unusual meteorite which is newly identified as a pyroxene-bearing pallasite. It consists mainly of Fe-Ni metal, olivine and pyroxene, and shows a porphyritic texture typical of most olivine, the same texture as that of all known pallasite meteorites. Yamato-8451 might have been classified as one of the common pallasites because of its exotic texture and mineral assemblage, a unique feature of pallasites, but it is highly unusual because it contains pyroxene. Most olivine and pyroxene crystals are well rounded to subrounded, but angular grains and grain aggregates are also recognized in the metallic host. Pyroxenes are mm-sized and consist of three different types in Ca content. These are : (1) exceptionally Ca-poor polysynthetic twinned orthopyroxene (under Wo 1.0), (2) Ca-poor non-polysynthetic twinned orthopyroxene (Wo 1.0-3.5) and (3) clinopyroxene (over Wo 40). The olivine composition is Fo 89.6 on average, the most magnesian known in all pallasites.}, pages = {1--10}, title = {Yamato-8451: A newly identified pyroxene-bearing pallasite}, volume = {8}, year = {1995} }