Macroscopically, in broken or sawed surfaces, MdR is a rather homogeneous microbreccia with only a possible suggestion of a light-dark brecciated structure. It has a medium gray color with fairly frequent but not very distinct chondrules, which break with the matrix. Thus it meets the criteria for the classic definition of "gray chondrites". The polished surfaces show a normal abundance of metal, for H, hight iron, common type chondrites. microscopically, in thin sections, MdR resembles many H5 chondrites. The usual types of chondrules occur barred olivine, radiating pyroxene, (and/or olivine) and porphyritic, some with "skeletal" or probable corroded olivines. One chondrules contains free silica, apparently tridymita, in small spherules with diopside. The overall texture of MdR exhibit the integration of chondrules and coarsely-crystalline matrix. The texture integration, the ocorrence of orthorrombic low Ca pyroxene only and the devitrified chondrule mesostasis glasses place MdR in the petrographic grade 5 of Van Schmus & Wood (1967). The feldspar component occurs mainly as microcrystalline aggregates in these mesostasis. Only a few clear intersticial feldspar grains were found.