Crystal Regeneration under Dissolution-Growth Conditions as a Factor of Enhancement of Gemstones

It is demonstrated by the example of gem-quality ruby, spinel, beryl, scapolite, kunzite, danburite, and jeremejevite from various deposits that, under the conditions of staged mineral formation, their later low-temperature generations are regenerated as a result of growth-dissolution and can acquire high gem-quality properties. These crystals formed under lower-temperature mineralization conditions. One of the characteristic features of such crystals, in addition to paragenetic associations, is their crystal morphology. The features of facet sculptures and internal structure, resulting from growth and dissolution, reflect their enhancement processes. These processes can occur both in parent rocks and in various types of cavities, such as pegmatite chambers, miaroles, or in crushed zones and fracture structures typically filled with later minerals, including loose aggregates and clay fractions.