The Yamato (Y)-8449 chondrite is a new CR (Renazzo-type) chondrite, and the constituent minerals coincide in chemical composition with those of the other CR chondrites except phyllosilicate and metal. FeO and Al_2O_3 contents of phyllosilicates in Y-8449 are richer than those in other CR chondrites. Fe-Ni metal in Y-8449 is classified into two types; one type has an exsolution texture indicating a slow cooling rate of the metal, and the other type has a massive texture free from exsolution texture. Massive Fe-Ni metal in Y-8449 is more homogeneous than that in the other CR chondrites. Groundmass glass and phenocrystic enstatite in Y-8449 chondrules have been replaced by phyllosilicate in the chondrule rims, and the aqueous alteration reaction that produced the phyllosilicate had possibly taken place in a nebula at low temperatures prior to accretion onto the parent body
