gems, beryl, emerald, Afghanistan, Panjshir

Quality and origin are important factors influencing the price of emeralds. Emeralds from different localities exhibit distinct gemmological characteristics that serve as key indicators for origin determination. This study investigates emerald samples from the Panjshir mining area in Afghanistan, using advanced analytical methods including optical microscopy, infrared spectroscopy, micro UV-visible–near-infrared spectroscopy, and Raman spectroscopy to examine their gemmological features, internal inclusions, chemical composition, and color origin. The color of the Afghan emeralds ranges from light green to dark green, with crystals commonly forming short hexagonal prisms or tabular shapes. Black and brown associated minerals are visible externally. Under the Chelsea filter, most samples exhibit localized red reactions. The primary inclusions are multiphase fluid inclusions—needle-like, shuttle-shaped, or tubular—containing rock salt, potassium salt, and solid minerals. Raman spectroscopy indicates that the liquid phase is predominantly H₂O, while solid inclusions are mainly calcite and hematite. Other mineral inclusions include hematite, calcite, amorphous carbon, quartz, carbonaceous matter, and apatite. LA-ICP-MS analysis shows that the main chemical components are BeO, Al₂O₃, and SiO₂, with trace elements including Ca, Mg, Ti, Li, Na, K, Rb, Cs, Cr, and V. Infrared spectroscopy reveals the presence of both Type I and Type II water, with Type II water showing stronger absorption, indicating a predominance of Type II water in these emeralds. This correlates with the high alkali metal content measured by LA-ICP-MS, as Type II water content is positively associated with alkali levels in beryl. UV-visible spectra confirm that Cr³⁺ and V³⁺ are the chromophores responsible for color. The gemmological, spectroscopic, and chemical characteristics of these Afghan emeralds provide a scientific basis for origin determination.