gems, lapis lazuli, Afghanistan, history of gemology, gem trade, Central Asia, Badakhshan, Sar-e-Sang

Wyart, Bariand and Filippi describe the lapis lazuli deposit of Sar-e-Sang in Badakhshan, Afghanistan, one of the historically important sources of the material. The paper examines the geological setting and mineralogy of the deposit, where lapis lazuli occurs in metamorphosed carbonate rocks, and discusses the constituent minerals of the lapis-bearing material. Particular attention is given to lazurite, the mineral responsible for the characteristic blue color, and to its association with calcite, pyrite, and other minerals. The authors relate the mineral assemblage to the geological conditions of formation and provide a mineralogical and geological characterization of Sar-e-Sang lapis lazuli and its host rocks.