I study the mineralogy, petrography, and mineral chemistry of refractory inclusions found in carbonaceous chondrites, using the optical microscope, scanning electron microscope, and electron microprobe. We may study whole inclusions, parts of inclusions, or even single crystals. We interpret the textures, mineral compositions, and bulk compositions of these objects in our attempts to determine how they formed. These objects are some of the first solids formed in the solar system, and study of them can give us important insights into the formation and early evolution of the solar system. In addition to a wide variety of inclusions in meteorites, I have studied several different types of meteorites, lunar samples from all the Apollo and Luna (Russian) sampling sites, and experimental run products on lunar and meteoritic compositions.