A type C asteroid, or chondrite asteroid, was a classification of asteroid.
In 2259, the USS Enterprise entered an asteroid field in its search for the Serene Squall. A scan of the field revealed an estimated 3,198,546 asteroids of this type. The asteroids ranged in radius from 610 kilometers to 8 meters. There were no dwarf planets in the field. The mean density of the field was 1-2 grams per cubic centimeter. The mean albedo was 0.23. (SNW: "The Serene Squall")
An unpopulated continent of Penthara IV was struck by a type C asteroid in 2368, causing heavy cloud cover that nearly led to a phenomenon not unlike the nuclear winters of 21st century Earth. (TNG: "A Matter Of Time")