Investigation of the Effects of High-Grade Metamorphism on the Quality of Badakhshan-Sarsang Lapis Lazuli

Abstract

This research was conducted to investigate the effect of metamorphism on the quality of lapis lazuli from the Sarsang mine of Karan and Manjan districts of Badakhshan province. Sarsang lapis lazuli mine is one of the most important lapis lazuli reserves in Afghanistan and the lapis lazuli stone in this region has different characteristics in terms of color, mineral composition, structure and quality. In this research, field, analytical-descriptive and laboratory methods were used and samples of lapis lazuli and adjacent rocks were collected and studied from different profiles of the mine. Geological studies show that the lapis lazuli deposits of Badakhshan are related to granitoids and metasomatosis of marbles and claspspheres has been involved in the formation of lapis lazuli rocks. The mineral composition of the samples includes minerals such as lazulite, diopside, calcite, dolomite, feldspars, scapolite, flagopite, forsterite and pyrite. The results of petrographic studies and XRF analysis show that the studied samples differ from each other in terms of mineral composition and the amount of chemical elements, and various metamorphic rocks, including micromarble, silicate marbles, pyroxene skarn, magnetite skarn and lapis lazuli, lapis lazuli and lapis lazuli, area are observed. According to the results in the paper, the processes of metamorphism and metasomatosis are closely related to the formation and characteristics of lapis lazuli host rocks and contribute to the mineral and qualitative differences of lapis lazuli.