Structural Study of Lapis Lazuli Stones and Beads of the Shahr-i Sokhta in Sistan

One of the most critical found objects from the site of Shahr-i Sokhta are lapis lazuli stones and beads, which were used as stone jewelry and ornaments. One of the site’s most significant archaeological and archaeometry topics is the way of manufacturing and types of stone structures into these objects. The Shahr-i Sokhta’s lapis lazuli beads manufactured with flint borers are in the forms of lens, lozenge, circle, etc., and were used as jewelry and ornaments such as bracelets, anklets, necklaces, etc. The main discussion in this research is recognizing the structure and studying the mineralogy of lapis lazuli beads discovered from Shahr-i Sokhta. Hence, by using laboratory-device methods such as petrography of thin sections, X-ray energy diffraction microanalysis, Raman Spectroscopy analysis, and gemology methods, this research studies the structures of three samples of lapis lazuli beads and stones of Shahr-i Sokhta. The results of laboratory studies show that Shahr-i Sokhta’s structure of lapis lazuli stone consists of lazurite minerals with a high percentage of calcite mineral impurities, which causes a reduction of transparency and purity of the lapis lazuli stones; also, elemental studies represent the presence of lazurite minerals. Raman structural and gemological studies show the structure, the amount of absorption coefficient, and its specific weight in the main structure of lapis lazuli stone. Chemical and structural studies indicate that the stones are similar in terms of composition.