We report measurements of an apparent magnetic-field-dependent absorption (imaginary part of the a.c. magnetic susceptibility) in superconducting Y1Ba2Cu3O7 ceramics and crystals. The absorption, which is observed over a wide range of frequencies but only when the material is below the superconducting transition temperature, is characterized by a narrow (∼ 30 Gauss FWHM at 6 MHz) peak and a wide (> 10 kG) feature, both of which are maximum at zero magnetic field. The absorption strength varies approximately as one over the square root of the frequency. The unusual magnetic-field-dependent peaks in the magnetic susceptibility are inherent in single grains and therefore do not originate from intergrain Josephson currents or multigrain (i.e., percolative) loops. The susceptibility peaks must be due to bulk behavior, interactons at grain surfaces, intragrain current loops, or intra-grain Josephson Junctions.