Briefly about the work of researchers writes Popular Mechanics. The authors studied pegmatites. This is the name of igneous rocks enriched with rare minerals. They may contain emerald, garnet, zircon, topaz and other precious stones. Crystals are formed from magma, that is, melt.
It is known that if the melt is cooled quickly, many small crystals will form. But in hundreds or thousands of years, large stones will form. However, pegmatites cool rather quickly, and in them, nevertheless, giant crystals were found.
Scientists ran mathematical simulations to figure out what was going on. As it turned out, water becomes an important factor in the crystal growth process. It can become part of the melt and remains there. Over time, the mass percentage of water in the melt grows, and at some point it becomes so much that a solution is obtained from the melt. In solution, diffusion and the rate of movement of atoms are higher, because of this, the rate of crystal growth increases significantly.