Let's analyze the difference between the realization of laboratory and natural hydrothermal processes. The crust begins to crystallize with the formation of, for example, granite. At the same time, start to separate the gaseous components from the melt, first of all water, in which the additions of mineralizers dissolve, which is able to dissolve substances that are insoluble under normal conditions. Such an aqueous gas solution is called hydrothermal. At the end of the magmatic crystallization, a cavity is formed in the thickness of the Earth's crust surrounded by strong walls, composed of crystalline rock, filled with a hydrothermal solution. "Extra" substance - crystals grow. Comparing the natural and laboratory hydrothermal processes, we see almost a complete analogy between them - in a natural and hermetic autoclave, not of iron, but of solid granite.