Veinides

Veinides are a proposed class of mineral-like crystalline compounds that form in hydrothermal vein systems within igneous and metamorphic rocks. The name reflects their vein-associated occurrence and the common -ide suffix used for mineral species.

Chemistry and structure: Veinides typically consist of metal cations coordinated by chalcogen or pnictide anions, creating layered or framework-type crystals. They exhibit strong intra-layer bonding with weaker inter-layer interactions, leading to anisotropic electrical and optical properties.

Formation and occurrence: Veinides precipitate from metal-rich fluids moving through fractures in host rocks, often alongside quartz, calcite, and sulfides. Natural specimens have been reported in hydrothermal belts where fluid activity concentrates metals.

Properties: Physical properties vary with composition but veinides are generally translucent to opaque, with metallic to pearly luster and variable hardness. They can show semiconducting or metallic behavior and are stable up to several hundred degrees Celsius, depending on composition.

Synthesis and potential applications: Laboratory synthesis via solid-state or hydrothermal methods allows study of their electronic and catalytic properties. Research explores uses in catalysis, energy storage, and as models for layered materials, though no commercial mineral standard currently exists.