Silica platelets (Corning 7940) were implanted sequentially with N at 52 keV to different doses ranging from 0 to 1.2×l017 ions cm2 and then with Fe at 160 keV to a dose of 6×10 ions cm2. The optical absorption decreased with increasing N1 dose at photon energies ranging from 1.4 eV to 6.5 eV. The relative intensity, S(0°), of the ferromagnetic resonance absorption and its resonance field, H(0°), at θ = 0° were larger than S(90°) and H,(90°) at 0 = 90°, where Θ is the angle between the applied magnetic field and the normal to the implanted surface. The maximum values of S(0°) and S(90°) were observed near the N/Fe atomic ratio of 0.2. At the similar atomic ratio, the differential relative intensity, S(0°)- S(90°), and the differential resonance field, H,(0°)-H,(90°). associated with the degree of magnetic interaction between the produced compounds, also showed maxima. We conclude that sequential ion-implantation of N1 and Fe1 into silica causes a chemical interaction to produce iron nitrides.