ABSTRACT
Nanometer-sized diamond has been found in meteorites, proto-planetary nebulae, and interstellar dusts, as well as in residues of detonation and in diamond £lms. It is known that primitive chondritic meteorites contain up to approximately 1500 ppm of nanometer-sized diamonds, containing isotopically anomalous noble gases, nitrogen, hydrogen, and other elements. These isotopic anomalies indicate that meteoritic NDs probably formed outside our solar system before the Sun’s formation (they are thus presolar grains).4 It appears that some interstellar emission bands in the 3-4, 7-10, and approximately 21 μm spectral regions could originate from NDs.5
