- Chester, Chester County, Pennsylvania, United States1
- Chesterfield, Hampshire County, Massachusetts, United States1
- Clarksville, Habersham County, Georgia, United States1
- Clubb Mountain, Lincoln County, North Carolina, United States8
- Connecticut, United States1
- Copiapo, Atacama, Chile1
- Copper Mine Hill, Cumberland, Providence County, Rhode Island, United States1
- Cornwall, England, United Kingdom8
- Cornwall, Lebanon (Dauphin) County, Pennsylvania, United States1
- Cornwall, Lebanon County, Pennsylvania, United States1
- Cuba1
- Cumberland County, Pennsylvania1
- Cumberland, Cumbria, England, United Kingdom2
- Cummington, Hampshire County, Massachusetts, United States3
- Delaware County, New York, United States1
- Derbyshire, England , United Kingdom1
- Derbyshire, England, United Kingdom16
- Devon, England, United Kingdom2
- Drammen, Buskerud County, Norway1
- Dundas, Zeehan District, Tasmania, Australia1