India.12, Kashmir.12, inclusions.5, corundum, sapphire, gems

Hänni examines more than 50 faceted Kashmir sapphires to establish reliable criteria for determining geographic origin. Microscopic investigation, supplemented in some cases by SEM-EDS analysis, confirms previously reported mineral inclusions including tourmaline, pargasite and zircon, while identifying additional inclusions such as plagioclase, uraninite, allanite and probable rutile. Other characteristic internal features include healed fissures, growth structures and zoning. The study also discusses spectral characteristics of Kashmir sapphire and the causes of its characteristic velvety appearance, which may involve growth disturbances, healed fissures, light scattering from inclusions and extremely fine fluid or mineral particles. Hänni stresses that “Kashmir sapphire” denotes geographic origin rather than a particular quality or color, and discusses the limitations and significance of laboratory origin determinations.