Gel Cusps and Crystal Growth in Gels

Abstract

Observations on the cusp-shaped ``cracks'' which form around crystals growing in gels are reported. It is shown that the cusps are interconnected, that the most common shape of the cusps is three-sided, that the cusp sides have a ridged structure, and finally, that the disposition of cusps around a growing crystal often displays a good deal of symmetry. It is concluded that the crystal is completely surrounded by liquid as it grows, and that this liquid is contained within a womb-like enclosure formed by the cusps surrounding a crystal. It is proposed that the surface of the womb made of the gel cusps acts like a membrane, and additional nutrients enter the womb through osmosis.