‘Dolomite problem’ that has puzzled scientists for centuries may have finally been solved

Despite centuries of attempts to precipitate dolomite in the laboratory, the geologically abundant mineral has remained stubbornly mysterious. But now an international collaboration of researchers believes it has discovered the key to dolomite formation in the lab – cycles of saturation.

Discovered by the French naturalist Déodat de Dolomieu over 200 years ago, dolomite (CaMg(CO₃)₂) is a calcium–magnesium carbonate mineral. Crystals can usually be grown in the lab from solutions that are more highly saturated than normally possible – supersaturated solutions. However, although thermodynamically stable, and geologically widespread, dolomite stubbornly refuses to grow in the lab at near ambient conditions from supersaturated solutions. The so-called dolomite problem ‘represents a fundamental mystery in crystal growth theory’ according to Wenhao Sun, a materials scientist at the University of Michigan, US.