Bulk attenuation occurs in the solid, polycrystalline regions of the earth due to the local mismatch of the elastic moduli of neighboring grains. A ratio of bulk to shear attenuation which is consistent with seismological whole earth models, Q&kgr;-1/Qμ-1 ~1%, is predicted for typical mineral assemblages of the mantle, based on viscoelastic theory. The resulting Q derived for the normal mode 0S0, 6000, is within the observed range.