The ion exchange phenomenon is well-known for crystalline materials including minerals. It has been confirmed experimentally that many microporous minerals representing different chemical classes are capable of cation exchange with salt solutions, including dilute ones, even under room conditions. No doubt that microporous minerals show ion-exchange properties also in nature. Numerous works are devoted to the experimental study and practical use of ion-exchange properties of minerals, especially microporous aluminosilicates (zeolites, clay minerals, etc.), whereas reactions and products of natural ion exchange were almost non-studied to recent time.