Chiral Water Structures on the Dolomite(104)-S Surface Enantiomer.

The particular distribution of dolomite over geological time scales and the challenges of growing dolomite under geological conditions in a laboratory setting are still some of the most intriguing scientific puzzles. So-called organogenic models that suggest the role of molecules, especially of extracellular polymeric substances in the liquid phase, in dolomite formation currently challenge the attempts to understand dolomite formation in the context of kinetic constraints. Here, we confirm the presence of chirality on dolomite(104) surfaces by atomic-scale imaging with noncontact atomic force microscopy. Two enantiomers are mapped at the two opposing crystal surfaces. Chiral signatures are further identified in the adsorption of single water molecules, and chirality transfer to a full water monolayer is imaged. Links between chiral specificity of dolomite growth and chiral selectivity of biomolecules on earth, mediated by the liquid phase, appear to be a so far overlooked jigsaw piece in understanding the formation processes of dolomite.