Abstract: Herewith is described a process to produce stable, non-pyrophoric silicon nanocrystals as an isolatable powder. The process includes comminuting a silicon feed in a solvent thereby forming a silicon nanoparticle slurry, admixing a dry (water free) reagent with the silicon nanoparticle slurry thereby forming a SiX-coated silicon nanoparticle slurry. The reagent is, preferably, selected from an oxide source, a sulfide source, or a carbide source; where the SiX-coated silicon nanoparticle includes a SiX coating on a silicon nanoparticle and the SiX coating is a silicon-oxide when the reagent is an oxide source, a silicon-sulfide when the reagent is a sulfide source, or a silicon-carbide when the reagent is a carbide source.