corundum, ruby, USSR.12, Tajikistan.12, inclusions.5, gems

Describes gem-quality rubies from a marble-hosted deposit in the Pamir Mountains of the then USSR, near the Chinese border. The stones range from red through reddish to violet-red and have SG 3.98, refractive indices nₑ 1.761–1.762 and nₒ 1.769–1.770, and birefringence 0.008. Microscopic features include twinning lamellae, healed fissures, fluid inclusions, rutile dust and distinct growth striae. Trace-element analysis detected chromium, iron and titanium; absorption spectra show the characteristic chromium bands, and the stones exhibit strong red fluorescence.