LAUSR

Abstract The article presents a method of observing and measurement the size of the growth of small crystalline particles in a solution droplet. Size measurement of small crystals in early stage of their growth is based on the analysis of optical diffraction patterns. The great advantage of this measurement method is the fact that it has no effect on the growth of the investigated crystals and, compared to microscopic methods, it provides a much larger area of observation. How to interpret diffraction patterns to use them to measure the size of the crystalline particles is illustrated by using a few examples of crystals with selected shapes and different orientations of their faces in space. All methods of interpreting diffraction patterns are justified by numerical calculations based on Fourier optics. The common features of diffraction patterns of crystals of different shapes and different orientations in space show that the presented method can be used to observe a small crystal of any shape and orientation growing in a droplet of solution.