Element composition by mass
Formula: BaCO₃ · molar mass: 197.34 g/mol
| Ba | 69.59% | |
| O | 24.32% | |
| C | 6.09% |
Computed from atomic weights (IUPAC 2021). Site-occupancy groups (Fe,Mn) split equally.
Witherite sits at 3–3.5 on the Mohs scale — can be scratched by a steel knife.
White
Orthorhombic
Witherite (BaCO₃) is barium carbonate — the carbonate analog of baryte (BaSO₄). Named after English chemist William Withering, it is the principal carbonate ore of barium. Witherite forms in low-temperature hydrothermal vein assemblages, often paired with galena and fluorite. Northumberland and Cumberland (England) are the historical type-area sources for collector specimens.
