Polished sections of the Jajh deh Kot Lalu enstatite chondrite have been studied microscopically. The composition of its minerals has been ascertained by means of local electron mieroprobe X-ray analysis. Well-analysed minerals and pure elements were used as standards. Corrections were made for wavelength shift, detector deadtime, background, mass absorption, secondary fluorescence, and atomic number. Oxygen, nitrogen, and carbon were measured quantitatively using newly developed dispersive detection systems. The following minerals were found and analyzed: enstatite, pigeonite, oligoclase, kamacite, troilite. oldhamite, daubreelite, ferro alabandite, schreibersite, graphite, and a new mineral, sinoite (silicon oxynitride, Si 2N 2O). The unusual mineral association, the chalcophilic behavior of Ti, Mn, Cr, Ca, the occurrence of Si in kamacite, and the presence of sinoite indicate that the meteorite was formed under strongly reducing conditions. Chemical-mineralogical relationships between enstatite achondrites and enstatite chondrites are discussed. The results suggest that enstatite achondrites may have originated via remelting of enstatite chondrite type stones with simultaneous gravitational separation under highly reducing conditions.