A grey-black mineral which is an oxide of manganese and copper and typically occurs as aggregates and coatings of thin plate-like crystals with a submetallic lustre.
Chemical formula: CuMnO₂. Crystal system: monoclinic.
Mid 19th century; earliest use found in James Nicol (1810–1879), geologist. From the name of C. F. H. Credner, German geologist and mineralogist, who conducted early research on this mineral + -ite, after German Crednerit.