#moonstone gem
- Adularia — A structural variety of orthoclase (potassium feldspar) presenting as transparent to translucent, colorless or whitish crystals, characterized by a specific silvery or opalescent schiller known as adularism. Named after the Adula Alps in Switzerland, where it was historically found within hydrothermal veins of metamorphic rocks. Due to its unique optical properties, fine specimens are cut as moonstones for gemology, while bulk materials are applied in high-grade ceramics and glass manufacturing.