Investigation of the Gemological Characteristics and Types of Inclusions of Emeralds from Sumbawanga, Tanzania

Africa hosts numerous emerald deposits, among which Sumbawanga, located at the junction of Tanzania, Zambia, Congo, and Malawi, stands out as one of the significant localities. This study presents a comprehensive analysis of the gemological, spectroscopic, and inclusion characteristics of Sumbawanga (Tanzania) emerald samples utilizing techniques such as gem microscopy, UV-Vis-NIR spectroscopy, Raman spectroscopy, GEM-3000, and EPMA, etc. These emerald crystals look like rolled pebbles and display a bluish-green coloration. They contain fingerprint-like fluid inclusions, which occasionally encompass a circular bubble (the gas phase is CO2). Sumbawanga emeralds are characterized by abundant mineral inclusions, including quartz, apatite, anhydrite, diaspore, chrysoberyl, rutile, hematite, and magnetite. Particularly diagnostic are the mineral inclusion of chrysoberyl twins and the assemblages of quartz and diaspore.