Opaque Minerals in the Yamato-74191 Chondrules

Opaque minerals occur often as phenocrysts in porphyritic chondrules. Troilite is common in comparison with metallic iron in chondrules, and is often distributed separately from metallic iron in a chondrule. Since some opaque minerals are included in silicate minerals, opaque minerals had crystallized in a chondrule before the crystallization of silicate minerals. Rare chromites are always in contact with troilites. These chromites, including some other meteoritic chromites, have cation deficiency in the B site. This cation deficiency may be interpreted by a substitution of 3Fe^=2Cr^+Vacancy. Chromites and olivines in chondrule crystallized in disequilibrium to each other