The name is derived from the Latin word calx meaning lime. Cobaltoan is an attribute due to the cobalt(II) in its crystal lattice substituting Ca(II) ions.
Cobaltoan calcite or cobaltocalcite is one of many varietes of calcite. In its structure Ca(II) ions are substituted by Co(II) ions giving it a characteristic color. The mineral adopts the same structure as calcite. It crystallizes in trigonal crystal system and it forms rhombohedral or scalenohedral crystals. The perfect cleavage in three direction is observed. It is formed at localities rich in Co(II).The world most famous localities are Morrocco, Congo, Italia and Spain. The specimen presented comes from Morrocco (valued at 50$). Nicely terminated pinky crystals arrise from the matrix in random direction.