C-type asteroid
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.
176 Iduna
Iduna (minor planet designation: 176 Iduna) is a large main-belt asteroid that was discovered by German-American astronomer Christian Heinrich Friedrich Peters on October 14, 1877, in Clinton, New York. It is named after Sällskapet Idun, a club in Stockholm that hosted an astronomical conference; Idun is also a Norse goddess. A G-type asteroid, it has a composition similar to that of the largest main-belt asteroid, 1 Ceres.