Atomic force microscope: A new tool for imaging crystal growth processes

We present real-time and in situ atomic force microscope (AFM) observations of solution growth on the cleavage plane of two minerals, calcite and fluorite. Different growth behaviours are exhibited: the calcite surface grows via a layer-spiral mechanism, while the fluorite surface grows via the formation of sharp asperities. The differences in behaviour of the two minerals may be linked to the lack of local charge neutrality on the fluorite surface. The growth mechanisms observed on calcite and fluorite provide insight into the expected behaviour of a wide range of salts important in nature and industry.