The biggest unequivocally C-type asteroid is 10 Hygiea , although the SMASS classification places the biggest asteroid 1 Ceres , here as well , because that scheme lacks a G-type . The largest unequivocally C-type asteroid is 10 Hygiea , although the SMASS classification places the largest asteroid 1 Ceres , here as well , because that scheme lacks a G-type .