GEMS (glass with embedded metal and sulfides) are a major subcomponent of one of the most primitive classes of interplanetary dust. GEMS are usually a few 1000 angstroms in diameter and are composed of glass with large numbers of 10nm size (100A) rounded grains of FeNi metal and sulfide. Individual GEMS show evidence of radiation processing consistent with exposure in the interstellar medium. GEMS may be preserved interstellar grains that were incorporated into early solar system bodies.