corundum, geology.11, Nepal.12, gems

Gem-quality rubies and fancy-color sap-phires have been recovered from dolomite marble lenses located high in the Himalayan mountains of east-central Nepal (Ganesh Himal). First discovered in the early 1980s, these deposits have had only limited and sporadic production because of their isolated locations, high altitudes, and harsh seasonal weather conditions. The pre-cise locations and geology of the two best-known deposits are described. In addition, 27 polished samples and 19 rough crystals and mineral specimens were thoroughly investigated to document their gemological characteristics and crystal morphology. The most distinctive internal features are their color-zoning characteristics, various cloud-like and other patterns, as well as a wide variety of mineral inclusions, some of which have not been seen in rubies from other sources.