Siledamaks

Siledamaks are a class of silica-rich mineral aggregates that form in high-temperature metamorphic settings, especially within subduction-zone rocks. They present as layered, glassy-to-microcrystalline masses with a characteristic iridescent sheen produced by nanoscale dopants such as iron or copper. The term siledamak combines a reference to silica with a local lithic root; it was coined by geologist Lila Aran in 2127 in reference to their silica-rich composition and distinctive appearance.

Formation and occurrence: Siledamaks develop when silica-rich fluids crystallize within veins in schist and quartzite during metamorphism under elevated pressures and temperatures. They are typically found in association with garnet, mica, and titanite, and are most extensively documented in the Dorin and Zalean belts, though individual outcrops vary in color and texture.

Physical properties: Siledamaks range from translucent to opaque, with a hardness of about 6 to 7 on the Mohs scale. They exhibit a glassy to microcrystalline fracture, a high refractive index, and can show iridescence under polarized light. They are relatively chemically inert and fracture conchoidally.

Uses and significance: In the mineral trade, high-quality siledamaks are cut as gemstones or used in decorative carvings. In geology, they are studied for insights into metamorphic fluid histories and crystallization under high-pressure conditions. Economic extraction is limited by the accessibility of deposits.

Discovery and nomenclature: Since their initial description in the early 22nd century, siledamaks have become a reference term in regional metamorphism studies, with multiple deposits named after associated host rocks.